JPH0520051Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a horizontal deflection linearity correction circuit used in various devices using cathode ray tubes (picture tubes).

(Prior Art) One of the problems with devices that display images using a picture tube that is deflected at a relatively wide deflection angle is that It is mentioned that the output reproduced image is stretched at both ends.

Generally, to horizontally deflect the electron beam of a picture tube using the electromagnetic deflection method, a sawtooth wave current for horizontal deflection is passed through a horizontal deflection coil attached to the neck of the picture tube. However, the manner in which the sawtooth wave current for horizontal deflection supplied to the horizontal deflection coil changes on the time axis is the eighth
As shown by curve a in the figure, if the electron beam changes at a constant rate on the time axis, the deflection angle per unit time of the electron beam of the picture tube is 9th.
As illustrated in the figure, the beam is deflected at a constant angle α.

On the other hand, the image display surface of a picture tube is curved with a large radius of curvature so that it is as close to a flat surface as possible, so the distance from the center of deflection of the picture tube to the image display surface is not constant. Therefore, when the deflection angle per unit time of the electron beam is constant as described above, the moving distance of the electron beam per unit time on the image display surface is the 9th
Since the moving distance at the periphery, exemplified by l' in the figure, is larger than the moving distance l at the center, even if you try to project an image with a constant grid spacing pattern on the image display surface, As illustrated in FIG. 10, the image projected on the image surface is in a state where the peripheral portion is elongated compared to the center portion.

The most common conventional solution to the above problem is to install a horizontal deflection coil 2 in series with a horizontal deflection coil 2 to which a sawtooth wave current for horizontal deflection is supplied from a horizontal deflection circuit.
A so-called S-shaped correction capacitor, which also serves as a direct current blocker, is connected to appropriately adjust the resonance period between the S-shaped correction capacitor and the horizontal deflection coil. The conventional method used uses the resonance effect between the S-shaped correction capacitor and the horizontal deflection coil to correct the waveform of the horizontal deflection current.
Good correction can be made when the horizontal deflection frequency is constant, but when the horizontal deflection frequency is switched to multiple levels, multiple S-shaped capacitors are used in response to the change in the horizontal deflection frequency. is required to be switched by a changeover switch.

However, because a large current flows through the S-shaped capacitor, the above-mentioned changeover switch is prone to arcing between the contacts each time the current is cut off, so in order to safely and reliably change the changeover switch, it is necessary to turn off the power to the device. This requires a complicated operation, such as having to switch the switch once it has been disconnected, and it is difficult to change the linearity of a part of the image, for example, the left edge of the image. Even if there were such demands, there was a problem in that they could not be easily met.

Therefore, in order to solve the above-mentioned problem, including the case where the horizontal deflection frequency is switched to a plurality of levels, the applicant company has developed a system that starts from the horizontal deflection circuit 1 as shown in FIG. In series with the horizontal deflection coil 2, which is supplied with a sawtooth current for horizontal deflection, there is a horizontal deflection linearity corrector LCA, i.e. one permanent magnet, as shown in FIGS. 4 to 6. 9, and a permanent magnet 9 arranged in such a manner that the magnetic flux generated by the permanent magnet 9 can be circulated in series.
Two saturable magnetic cores 7 and 8 are respectively provided in contact with the two magnetic poles forming a pair and are spaced apart from each other, and are wound around the two saturable magnetic cores 7 and 8, respectively. When the windings 10 and 11, which are respectively wound around the two saturable magnetic cores 7 and 8 described above, are connected in series and a current is passed through them in a certain direction, the two The magnetic flux generated by the respective windings 10 and 11 wound around the saturable magnetic cores 7 and 8, respectively, is added to the magnetic flux generated by the permanent magnet 9 in one saturable magnetic core, and in the other saturable magnetic core. 2 wound around the two saturable magnetic cores 7 and 8 so as to be subtracted from the magnetic flux by the permanent magnet 9.
The connection polarity of the two windings 10 and 11 is determined, and the series-connected windings are connected to the horizontal deflection coil 2 of the picture tube.
By connecting a horizontal deflection linearity correction device LCA, which is essentially connected in series with the horizontal deflection linearity correction device LCA, the sawtooth wave current for horizontal deflection has a steep slope in the center like the waveform b shown by the dotted line in Fig. 7. The specification of Japanese Patent Application No. 182,574/1983 proposes a solution in which the above-mentioned problem is avoided by making the inclination gentle at both ends.

In FIG. 3, which shows a block diagram of a horizontal deflection circuit to which the horizontal deflection linearity correction device LCA, which has been proposed by the applicant company and is configured as shown in FIGS. 4 to 6, is connected. 1 is a horizontal deflection output circuit, 2 is a horizontal deflection coil, and LCA is a horizontal deflection linearity correction device.

Further, c and d in the figure are terminals of the horizontal deflection linearity correction device, and these terminals c and d are used in the horizontal deflection linearity correction device LCA shown in FIGS. 4 to 6, respectively. They correspond to terminals c and d, respectively.

Reference numeral 5 in FIG. 3 is a capacitor for blocking the DC component, and this capacitor 5 is connected to the horizontal deflection coil 2.
Its capacitance value is selected to be a large value so that its impedance is sufficiently small at the frequency of the horizontal deflection current applied to it. That is, in the circuit arrangement shown in FIG. 3, the waveform of the horizontal deflection current is not corrected by the resonance effect between the capacitor and the horizontal deflection coil 2, as in the conventional circuit described above, but by the correction of the waveform of the horizontal deflection current. The waveform is corrected by the horizontal deflection linearity corrector LCA.

Now, in the previously proposed horizontal deflection linearity correction device shown in FIGS. 4 to 6, 7 and 8 are drum cores made of a ferromagnetic material having saturable magnetic properties, such as ferrite. , also 9
1 is a permanent magnet, and 10 and 11 are windings wound around the drum cores 7 and 8 described above.

The drum cores 7 and 8 described above are individually in contact with the two magnetic poles N and S forming a pair in the permanent magnet 9 in an arrangement such that the magnetic flux generated by one permanent magnet 9 can be circulated in series, The windings 10 and 1 are provided in a spaced apart state and are wound around the two drum cores 7 and 8, respectively.
1 are connected in series.

The connection polarity of the two windings 10 and 11 wound on the two drum cores 7 and 8, respectively, is the same as that of the two windings 7 and 8 that are connected in series.
When a current i in a certain direction is passed through the two drum cores 7 and 8, magnetic fluxes φ1 and φ2 are generated in the windings 10 and 11 respectively wound on the two drum cores 7 and 8, and as for one drum core 7, the magnetic fluxes φ1 and φ2 are generated as described above. magnet 9
The magnetic flux φ3 is added to the other drum core 7.
is determined to be subtracted from the magnetic flux φ3 caused by the permanent magnet 9. is the opposite, the magnetic fluxes φ1 and φ2 generated in the respective windings 10 and 11 wound around the two drum cores 7 and 8 are equal to the magnetic flux φ1 of one drum core 7 and the magnetic flux φ1 of the drum core 7, respectively. For the other drum core 8, the magnetic flux φ2 of the other drum core 8 is added to the magnetic flux φ3 of the permanent magnet 9}.

In any of the previously proposed horizontal deflection linearity correction devices shown in FIGS. 4 to 6, the magnetic flux φ3 generated from one permanent magnet 9 is divided into two The magnetic flux φ1 generated by the current i flowing through the winding 10 wound around the drum core 7 is configured to flow back to the drum cores 7 and 8 in series, so that the magnetic flux φ1 does not flow back to the drum core 8. The magnetic flux φ2 generated by the current i flowing through the winding 11 wound around the drum core 8 is prevented from flowing back to the drum core 8.

Therefore, the inductance L10 of the winding 10 wound around the drum core 7 and the drum core 8
Inductance L11 of winding 11 wound in
The curves L10 and L11 in FIG. 7 change in response to changes in the polarity and magnitude of the current i applied thereto.

That is, when the current i flowing through the winding 10 is positive, the inductance of the winding 10 wound around the drum core 7 increases as the drum core 7 becomes saturated as the current i increases. The inductance L10 of the winding 10 being turned is
It decreases as the current i flowing through the winding 10 increases, and when the current i flowing through the winding 10 is negative, the magnetic flux density in the drum core 7 decreases as the current i increases. The inductance L10 of the winding 10 wound around the drum core 7 is
The inductance of the winding 11 wound around the drum core 8 increases as the current i flowing through the winding 10 increases.On the other hand, when the current i flowing through the winding 11 is negative, the inductance increases. Since the drum core 8 becomes saturated as i increases, the inductance L11 of the winding 11 wound around the drum core 8 decreases as the current i flowing through the winding 11 increases. When the flowing current i is positive, the inductance of the winding 11 wound around the drum core 8 decreases because the magnetic flux density in the drum core 8 decreases as the current i increases.
L11 increases as the current i flowing through the winding 11 increases.

Therefore, the series inductance of the two windings 7 and 8 described above, that is, the inductance L between terminals c and d in the horizontal deflection linearity correction device
(10+11) is the minimum inductance at the point where the current i is zero, as shown in the curve L(10+11) in FIG. 7, which is a combination of the curves L10 and L11 in FIG. It increases as the current increases regardless of whether it increases in the positive or negative direction, and a sawtooth shape as shown in the lower part of FIG. When a wave current i is applied, the inductance value between terminals c and d of the horizontal deflection linearity correction device LCA becomes the largest corresponding to the positive and negative peak values of the sawtooth wave current, and is the largest in the center. Changes to become smaller.

Therefore, in the horizontal deflection linearity correction circuit shown in FIG. 3, where the previously proposed horizontal deflection linearity correction device LCA shown in FIGS. The sawtooth wave current flowing through the deflection coil 2 has a slope that becomes gentler at the beginning and end of the sawtooth wave, as shown by the dotted curve b in FIG. By using the horizontal deflection linearity correction device LCA, the occurrence of image distortion as shown in FIG. 10 can be effectively prevented.

(Problem to be solved by the invention) However, since the horizontal deflection current that actually flows through the horizontal deflection circuit is not a perfect straight line as shown by the broken line c in FIG. When an image is displayed on an image display screen by performing electromagnetic deflection using a horizontal deflection current whose horizontal deflection linearity has been corrected using the proposed horizontal deflection linearity correction device LCA, the reproduced image obtained will not be symmetrical. That became a problem. In order to solve the above-mentioned problems, for example, by adjusting the number of turns of the windings 10 and 11 individually wound around the drum cores 7 and 8, the manner of correction of the waveform of the horizontal deflection current can be adjusted arbitrarily. It is also possible to change it.

However, even when the solution described above is applied, fine adjustments may be required due to variations in the sets and windings. This is done by unwinding or adding windings to the deflection linearity coil, but since such fine adjustment is impossible, the windings individually wound around the drum cores 7 and 8 are Either line 10 or 11,
Alternatively, a solution is to wind a secondary winding around both, connect a load circuit to it, and change the current value flowing to the load in accordance with the set variation, thereby making the above-mentioned fine adjustment. was suggested.

By the way, the scanning standards to be applied when reproducing images, for example, in the case of television receivers, often differ depending on the standard system of the television system that is being received. When it comes to display devices used in various information devices, the scanning standards are often so different that each device manufacturer sets their own scanning standards. If the scanning standards are different, as in the case of different scanning standards, the configuration of the deflection circuit will naturally be different. As is well known, many types of deflection circuits that can be used for multiple scanning standards have been proposed, since production is carried out in small quantities with a wide variety of products, which is disadvantageous in terms of production control and cost. However, as a horizontal deflection circuit that can be used for multiple scanning standards as described above, one of the windings 10 and 11 individually wound around the drum cores 7 and 8 as described above,
Alternatively, a configuration may be used in which a secondary winding is wound around both, a load circuit is connected to it, and the current value flowing to the load is varied in accordance with the variation in the set, thereby performing the above-mentioned fine adjustment. If
Even if the load circuit described above is compatible with a certain horizontal deflection frequency, the load circuit described above may become incompatible when the horizontal deflection frequency is switched to another frequency.

The above point will be specifically explained as follows. As shown in Fig. 3, the horizontal deflection coil 2 to which the sawtooth wave current for horizontal deflection is supplied from the horizontal deflection circuit 1 has a horizontal deflection linearity correction device LCA and a DC blocking capacitor connected in series thereto. 5 is connected, but if a deflection circuit that can be used for multiple scanning standards is constructed with such a circuit arrangement, within the range of change of the horizontal deflection frequency, the horizontal deflection The impedance of the DC blocking capacitor 5 through which a large horizontal deflection current flows is sufficiently small within the range of change in the horizontal deflection frequency so that no adverse effects are caused by the resonance between the coil 2 and the DC blocking capacitor 5. As such, it is necessary to use a capacitor with a large capacitance value as the DC blocking capacitor 5 mentioned above.

In other words, if the horizontal deflection frequency change range is 14KHz to 36KHz, the linearity correction device LCA
If the characteristics are designed to be optimal in the high frequency range 20KHz to 36KHz where no adverse effects of resonance appear, the capacitance value of the DC blocking capacitor 5 will be insufficient in the frequency range 14KHz to 20KHz. This is because a shrinkage phenomenon on the right side of the reproduced screen inevitably occurs due to the adverse effect of the resonance effect.

By the way, as is well known, the reactance of a capacitor increases in inverse proportion to the frequency, but if the range of change in the horizontal deflection frequency is 14KHz.
To explain the case of ~36KHz as an example, the above-mentioned DC blocking capacitor 5 has a capacitance value that exhibits a sufficiently small reactance in the horizontal deflection frequency range of 20KHz to 36KHz, for example. Even if the horizontal deflection frequency is set to 14 KHz to 20 KHz, a large impedance will be exhibited in the low frequency portion within the frequency change range of 14 KHz to 20 KHz.

Therefore, in order to solve the above-mentioned problems, the DC blocking capacitor 5 provided in the circuit layout is designed to reduce the impedance in the low frequency region in the horizontal deflection frequency change range, as illustrated in FIG. The capacitor 5b to achieve
It is possible to connect it in parallel to the capacitor 5a,
The capacitor 5a mentioned above is 8.2μF (withstand voltage 200V)
A polypropylene capacitor of 10 μF (withstand voltage 160 V) was used as the capacitor 5b described above, and both capacitors 5
Attempts have been made to construct a DC blocking capacitor 5 by connecting capacitors a and 5b in parallel.

The polypropylene capacitor with a withstand voltage of 200 V used in the configuration of the DC blocking capacitor 5 described above has excellent frequency characteristics and ripple resistance characteristics, but it is especially recommended for capacitors with a withstand voltage of 200 V and a capacitance value larger than 10 μF. The electrolytic capacitor 5b, which was made to order and had a considerably large shape, and which was used in the configuration of the DC blocking capacitor 5 described above, was as follows.
Specially ordered product with excellent ripple resistance and heat resistance.
It is a 10μF (withstand voltage 160V) electrolytic capacitor, and its external shape is also quite large, but it goes without saying that using a large capacitor will cause problems in terms of the shape of the board on which it is mounted. do not have.

Therefore, as described above, it is necessary to configure the DC blocking capacitor 5 with a large capacitance value, which is necessary to prevent the adverse effects of resonance from occurring even in the low frequency range of the horizontal deflection frequency change range. For this reason, the two parallel capacitors 5a and 5b that constitute the DC blocking capacitor 5 were also used with capacitance values as described above. In the configuration example shown in FIG. Each element constituting the deflection circuit, for example, a horizontal output transistor,
Due to the impedance of the damper diode, the horizontal deflection coil 2, the DC blocking capacitor 5, etc., the waveform of the sawtooth current becomes like curve c in Figure 8, which causes the expansion on the left side and the contraction on the right side of the playback screen. Coupled with this, the reproduced image becomes one with degraded linearity.

In order to solve the above problems, one permanent magnet and two magnetic poles forming a pair in the permanent magnet are arranged in such a manner that the magnetic flux generated by the permanent magnet can be circulated in series. Two saturable magnetic cores that are in contact with each other and spaced apart from each other, and windings that are respectively wound around the two saturable magnetic cores, and the two saturable magnetic cores are When the respective windings are connected in series and a current is passed through them in a certain direction, the magnetic flux generated by the respective windings respectively wound around the two saturable magnetic cores is It is wound around the two saturable magnetic cores so that the saturated magnetic core is added to the magnetic flux from the permanent magnet, and the other saturable magnetic core is subtracted from the magnetic flux from the permanent magnet. The connection polarity of the two windings is determined, and the series-connected windings are connected substantially in series with the horizontal deflection coil of the picture tube, and the windings are wound respectively around the two saturable magnetic cores. A horizontal deflection linearity correction circuit has been proposed in which a secondary winding is wound around one of the wires, and a load circuit is connected to the secondary winding via a switch.

By the way, when a resistive load circuit is connected to the secondary winding as in the previously proposed circuit, the inductance represented by the inductance shown by curve L11 in Fig. 7 becomes equivalently small. , the positive side of the current i becomes smaller and the right side of the playback screen is enlarged, in line with the original purpose.
At the same time, the negative side of the current i also decreases, so the left side of the playback screen also expands, so the correction effect on the right side of the screen is relatively reduced, making the correction effect likely to be insufficient. There were drawbacks such as increased size, and a solution was sought.

(Means for Solving the Problems) The present invention includes one permanent magnet and a pair of permanent magnets arranged in such a manner that the magnetic flux generated by the permanent magnet can be circulated in series. The two saturable magnetic cores are provided in contact with the two magnetic poles individually and are spaced apart from each other, and the windings are respectively wound around the two saturable magnetic cores. When the windings respectively wound around the saturable magnetic cores are connected in series and a current is passed through them in a certain direction, the magnetic flux generated by the windings respectively wound around the two saturable magnetic cores is , the two saturable cores are wound so that in one saturable core, the magnetic flux is added to the magnetic flux by the permanent magnet, and in the other saturable core, it is subtracted from the magnetic flux by the permanent magnet. The connection polarity of the two windings being turned is determined, and the series-connected windings are substantially connected in series with the horizontal deflection coil of the picture tube, and are wound respectively around the two saturable magnetic cores. A secondary winding is wound around the winding that dominates the right side of the screen, and a series connection circuit of a switch, a diode, and a load circuit for changing linearity is connected to the secondary winding. The above-mentioned problems are solved by providing a horizontal deflection linearity correction circuit.

(Example) Hereinafter, specific contents of the horizontal deflection linearity correction circuit of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a circuit diagram of one embodiment of the horizontal deflection linearity correction circuit of the present invention, and FIG. 2 is a circuit diagram for explaining the operation of the horizontal deflection linearity correction circuit shown in FIG. The horizontal deflection linearity correction circuit according to the invention includes the windings 10 and 10 respectively wound around the two saturable magnetic cores 7 and 8 in the previously proposed horizontal deflection linearity correction device described with reference to FIG. 1
The secondary winding 1 is attached to the winding that dominates the right side of the screen in 1.
This horizontal deflection linearity correction circuit has a configuration in which a load circuit R for changing linearity is connected to the secondary winding 14 of the coil 14 through a switch SW and a diode D. The on/off operation of the switch SW described above is performed by the control signal generation circuit CC in response to, for example, switching operation between a frequency range where the horizontal deflection frequency is low (e.g., 14KHz to 20KHz) and a high frequency range (e.g., 20KHz to 36KHz). This is done by a switching control signal supplied to the switch from the switch.

In FIG. 1, 7 and 8 are drum cores made of a ferromagnetic material having saturable magnetic properties, such as ferrite, 9 is a permanent magnet, and 10 and 11 are the drum cores 7, The winding 8 is wound around, and the numeral 14 is a secondary winding.

In the horizontal deflection linearity correction circuit shown in FIG. 1 and FIG. Although it is shown as being wound on the winding 11, when implementing the present invention, the above-mentioned 2
A drum core (drum-shaped core) in which the next winding is made of a ferromagnetic material (such as ferrite) that has saturable magnetic properties depending on the polarity of the permanent magnet and the winding direction.
It may be wound on the winding 10 which is wound on the winding 7.

The drum cores 7 and 8 mentioned above are arranged in such a manner that the magnetic flux generated by the permanent magnet 9 can be circulated in series, and are in contact with the two magnetic poles N and S forming a pair of the permanent magnet 9, respectively, and are mutually connected. The windings 10 and 11 wound around the two drum cores 7 and 8, respectively, are connected in series.

The connection polarity of the two windings 10 and 11 wound around the two drum cores 7 and 8, respectively, is the same as that shown in the fourth diagram, and the two windings connected in series are the same as those shown in the fourth diagram. When a current i in a certain direction is passed through the drum cores 7 and 8, 1 is applied to each of the windings wound around the two drum cores 7 and 8, respectively.
The magnetic fluxes φ1 and φ2 generated at points 0 and 11 are added to the magnetic flux φ3 caused by the permanent magnet 9 described above for one drum core 7, and subtracted from the magnetic flux φ3 generated by the permanent magnet 9 described above for the other drum core 7. {If the direction of the constant current i flowing through the two series-connected windings 7 and 8 is opposite to the above, the two drum cores 7 and 8 The magnetic fluxes φ1 and φ2 generated in the respective windings 10 and 11 are the magnetic flux φ1 of one drum core 7 and the magnetic flux φ3 due to the permanent magnet 9 described above.
and for the other drum core 8, it is added between its magnetic flux φ2 and the magnetic flux φ3 from the permanent magnet 9}.

Now, the switch SW in the horizontal deflection linearity correction circuit of the present invention shown in FIG. 1 is turned off, and the diode D connected to the secondary winding 14 and the load for linearity change are Considering the horizontal deflection linearity correction circuit of the present invention in a state where no current flows through the circuit R and the secondary winding 14, in this case, the inductance L10 of the winding 10 wound around the drum core 7 described above and , the inductance L11 of the winding 11 wound around the drum core 8 changes as shown by curves L10 and L11 in FIG. Winding wire 10 wound around drum core 7
The inductance of the current i flowing through the winding 10 is
is positive, the drum core 7 becomes saturated as the current i increases, so the inductance L10 of the winding 10 wound around the drum core 7 decreases as the current i flowing through the winding 10 increases. , and when the current i flowing through the winding 10 is negative,
Since the magnetic flux density in the drum core 7 decreases as the current i increases, the inductance L10 of the winding 10 wound around the drum core 7 is
On the other hand, when the current i flowing through the winding 11 is negative, the inductance of the winding 11 wound around the drum core 8 increases as the current i flowing through the drum core 8 increases. As the drum core 8 increases, the drum core 8 becomes saturated.
Inductance L11 of winding 11 wound in
decreases as the current i flowing through the winding 11 increases, and when the current i flowing through the winding 11 is positive, the magnetic flux density in the drum core 8 decreases as the current i increases. , the inductance L11 of the winding 11 wound around the drum core 8
increases as the current i flowing through the winding 11 increases, and the series inductance of the two windings 7 and 8, that is, the inductance L (10
+11) is the minimum inductance at the point where the current i is zero, as shown in the curve L(10+11) in FIG. 7, which is a combination of the curves L10 and L11 in FIG. Regardless of whether the increase is positive or negative, it increases as the current increases, and the seventh
The inductance value between the terminals c and d of the horizontal deflection linearity correction circuit when the sawtooth wave current i shown in the lower part of the figure is caused to flow is the positive and negative peak values of the sawtooth wave current. corresponds to the largest,
It changes so that it becomes the smallest in the center.

The operation of the horizontal deflection linearity correction circuit of the present invention when no current flows through the secondary winding 14 is the same as the operation of the previously proposed horizontal deflection linearity correction device LCA described with reference to FIGS. 4 to 6. However, in the horizontal deflection linearity correction circuit of the present invention, one of the windings 10 and 11 wound on the two saturable magnetic cores 7 and 8 in the horizontal deflection linearity correction device A diode D and a load circuit R for changing the linearity are connected to the secondary winding 14 wound on top of the secondary winding 14 via a switch SW, and when the switch SW is turned on, the secondary winding A diode D and a load circuit R for changing linearity are connected to the switch 14 via a switch SW, and a current is passed through the load circuit R to perform fine adjustment.

FIG. 2 is a circuit diagram for explaining the operation of the horizontal deflection linearity correction circuit of the present invention shown in FIG. 1, and the windings 10 and 1 shown in FIG.
The black circles near the ends of the windings 1 and 1 indicate the polarity of each winding. In the horizontal deflection linearity correction circuit shown in FIG.
The polarity of the windings is determined so that when the magnetic fluxes flow into the windings 10 and 11, a magnetic flux is generated in the direction in which the magnetic flux exits from the end on the black circle side.

2 which is wound on the winding 11 in FIG.
Diode D is connected to the next winding 14 via switch SW.
When the load circuit R for linearity change is connected to the secondary winding 14, and a current i2 flows through the secondary winding 14, the self-inductance of the winding 11 is L11, the induced voltage generated in the winding 11 is E, and the winding The mutual inductance between the wire 11 and the secondary winding 14 is M, and the current flowing through the winding 11 is
i1, self-inductance of secondary winding 14 L14, 2
Assuming that the current flowing through the next winding 14 is i2, the resistance value of the load circuit R for changing linearity is R, and the time is t, the following equation holds true as is well known.

{(L11)di1/dt}-(Mdi2/dt)=E......(1) −{Mdi1/dt}+{(L13)di2/dt}+Ri2=0
...(2) That is, by changing the resistance R in equation (2) above, the current i2 can be changed freely, and as a result, the second term on the left side of equation (1) {-Mdi2/dt}
The inductance of winding 11 can be changed
L11 will be changed equivalently.

However, the connection polarity of the diode described above, for example, if the winding 11 is the winding that dominates the right side of the screen, the self-inductance L11 is equivalently determined by Mdi2/dt of the second term on the left side of equation (1) described above. It is uniquely determined according to the polarity of the winding 11 and the secondary winding 14 so that it becomes small.

The above points will be explained with reference to FIG. 2 as follows. That is, in FIG.
If we assume that the period during which the current flows from the black circle corresponds to the right side of the screen, the black circle in the secondary winding 14 will be as shown in FIG. An induced voltage of (di1)/dt is generated, but if the connection polarity of the diode D is determined so that the diode D conducts due to the polarity voltage as described above, the voltage from the secondary winding 14 to the winding 11
An induced voltage M(di2)/dt is generated in the direction opposite to the black circle mark in the winding 11, so that more current flows through the winding 11. In other words, the inductance of the winding 11 is increased. The connection polarity of the diode D is uniquely determined according to the polarity of the winding 11 and the secondary winding 14 so that the diode D is equivalently small.

Then, as described above, a series circuit of a diode D and a load circuit R for changing linearity is connected to the secondary winding 14 wound on the winding 11 via the switch SW, and the secondary winding is connected to the secondary winding 14 wound on the winding 11. 14 to change the self-inductance L11 of the winding 11 equivalently, the self-inductance L11 of the winding 11 shown in FIG. Only the side can be changed,
Furthermore, the diode D makes it possible to prevent the negative inductance value of the self-inductance L11 of the winding 11 from decreasing, making it possible to completely change the linearity only on the right side of the screen.

(Effects of the invention) As is clear from the above detailed explanation, the horizontal deflection linearity correction circuit of the present invention solves various problems in the conventional horizontal deflection linearity correction circuit described above, and All the problems in the linearity correction circuit can be solved satisfactorily.

In other words, in a horizontal deflection circuit configured so that the horizontal deflection frequency can be switched between multiple types, in order to always obtain good linearity even when the horizontal deflection frequency is switched high or low, for example, As the DC blocking capacitor 5 (S-shaped correction capacitor 5) connected in series to the horizontal deflection coil 2, resonance between the horizontal deflection coil 2 and the DC blocking capacitor 5 described above is performed within the range of change of the horizontal deflection frequency. A capacitor with a large capacitance value is used so that the impedance of the DC blocking capacitor 5, through which a large horizontal deflection current flows, is sufficiently small within the range of change in the horizontal deflection frequency so that no adverse effects will occur due to the action. However, polypropylene capacitors, which have excellent frequency characteristics and ripple resistance characteristics,
For example, an electrolytic capacitor with a withstand voltage of 200 V and a capacitance value of 10 μF or more must be specially ordered and has a considerably large shape.Also, a specially ordered electrolytic capacitor with excellent ripple resistance and heat resistance characteristics has a large external shape. Moreover, the use of such a large capacitor as mentioned above not only increases costs, but also creates problems in terms of the shape of the board on which it is mounted, so such a solution is not recommended. Therefore, for example, if the horizontal deflection frequency change range is 14KHz to 36KHz, DC blocking with the capacitance value set to be optimal in the high frequency range 20KHz to 36KHz where the negative effects of resonance effects do not appear. If the circuit is designed using a linearity correction capacitor and a linearity correction coil, the capacitance value of the DC blocking capacitor 5 will be insufficient in the frequency range of 14KHz to 20KHz, and the negative effects of resonance will occur. This causes a shrinkage phenomenon on the right side of the playback screen.

In addition, when a resistive load circuit is connected to the secondary winding as in the already proposed circuit of the applicant company mentioned above, the inductance shown by the inductance shown by the curve L11 in FIG. becomes equivalently smaller, and the current i
The positive side of the current i becomes smaller and the right side of the playback screen is enlarged, but at the same time, the negative side of the current i also becomes smaller, so the left side of the playback screen is also enlarged, so the right side of the screen becomes relatively smaller. The correction effect tends to be reduced and the correction effect becomes insufficient, and there are also disadvantages such as the horizontal size being enlarged.

However, the horizontal deflection linearity correction circuit of the present invention
one permanent magnet, each of which is in contact with the two magnetic poles of the pair of the permanent magnet in an arrangement such that the magnetic flux generated by the permanent magnet can be circulated in series, and is spaced apart from each other; two saturable magnetic cores provided in a state of When the two saturable magnetic cores are connected and a current is passed through them in a certain direction, the magnetic flux generated by the respective windings wound around the two saturable magnetic cores is the magnetic flux generated by the permanent magnet for one of the saturable magnetic cores. The connection polarity of the two windings wound around the two saturable magnetic cores is determined so that the flux is added to the magnetic flux generated by the permanent magnet in the other saturable magnetic core. , the series-connected windings are substantially connected in series with the horizontal deflection coil of the picture tube, and the windings dominating the right side of the screen among the windings respectively wound around the two saturable magnetic cores; By winding a secondary winding around and connecting a series connection circuit of a switch, a diode, and a load circuit to the secondary winding,
A diode D and a load circuit for linearity change are connected to the secondary winding 14 wound on the winding that dominates the right side of the screen through a switch SW in the windings wound around two saturable magnetic cores. Connect the series circuit with R to flow current i2 to the secondary winding 14, and equivalently calculate the self-inductance of the winding that dominates the right side of the screen in the windings wound around the two saturable magnetic cores. When changing, only the + side in Figure 7, which is the dominant area of the self-inductance of the winding that dominates the right side of the screen, of the windings wound around the two saturable magnetic cores, respectively. In addition, the diode D can prevent the self-inductance of the winding from decreasing in the inductance value on the negative side in Figure 7, making it possible to completely change the linearity only on the right side of the screen. According to this invention, the conventional problems can be solved satisfactorily.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of one embodiment of the horizontal deflection linearity correction circuit of the present invention, FIG. 2 is a circuit diagram for explaining the operation of the horizontal deflection linearity correction circuit shown in FIG. 1, and FIGS. 3 and 11. is a block diagram of a horizontal deflection linearity correction circuit using the previously proposed horizontal deflection linearity correction circuit, FIGS. 4 to 6 are block diagrams of the previously proposed horizontal deflection linearity correction device, and FIG. 7 is a characteristic curve. As an example, FIG. 8 is a waveform diagram of a sawtooth wave current, FIG. 9 is an explanatory diagram of problems in a wide deflection angle picture tube, and FIG. 10 is an explanatory diagram of image distortion. 1...Horizontal deflection output circuit, 2...Horizontal deflection coil, 5...Capacitor, 7, 8...Drum core,
9... Permanent magnet, 10, 11... Winding wire, LCA...
...Horizontal deflection linearity correction device, 14...Secondary winding,
R...Load circuit for linearity change, SW...Switch, D...Diode.

Claims (1)

[Scope of utility model registration request] one permanent magnet, each of which is in contact with the two magnetic poles of the pair of the permanent magnet in an arrangement such that the magnetic flux generated by the permanent magnet can be circulated in series, and is spaced apart from each other; two saturable magnetic cores provided in a state of When the two saturable magnetic cores are connected and a current is passed through them in a certain direction, the magnetic flux generated by the respective windings wound around the two saturable magnetic cores is the magnetic flux generated by the permanent magnet for one of the saturable magnetic cores. The connection polarity of the two windings wound around the two saturable magnetic cores is determined so that the flux is added to the magnetic flux generated by the permanent magnet in the other saturable magnetic core. , the series-connected windings are substantially connected in series with the horizontal deflection coil of the picture tube, and the windings dominating the right side of the screen among the windings respectively wound around the two saturable magnetic cores; A horizontal linearity correction circuit is formed by winding a secondary winding around the wafer, and connecting a series connection circuit of a switch, a diode, and a load circuit for changing linearity to the secondary winding.