JPS6243269A - Correcting device for horizontal deflection linearity - Google Patents

Abstract

PURPOSE:To obtain a compact and inexpensive correcting device by defining the connection polarities of two windings so that the magnetic flux produced by a winding is added with the magnetic flux produced by a permanent magnet in terms of a saturable magnetic core at one side and then undergoes subtraction with the magnetic flux of the permanent magnet within a saturable magnetic core at the other side. CONSTITUTION:Drum cores 7 and 8 contact with a pair of magnetic poles N and S of a permanent magnet 9 in a distribution mode where the magnetic flux produced by the magnet 9 is circulated in series. At the same time, both drums cores 7 and 8 are set separate from each other. The connection polarities of both windings 10 and 11 wound round the drums 7 and 8 are defined so that the magnetic fluxes phi1 and phi2 produced to both windings 10 and 11 when a current (i) of a fixed direction is flowed are added with a magnetic flux phi3 produced by the magnet 9 with the core 7 at one side and undergoes subtraction with the flux phi3 with the core 8 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a horizontal deflection linearity correction device used in various devices using a (picture tube) cathode ray tube.

(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, the electron beam of a picture tube is deflected horizontally using the electromagnetic deflection method by passing a sawtooth wave current for horizontal deflection through a horizontal deflection coil attached to the neck of the picture tube. As shown in the 8 curves in Figure 6, the current changes on the time axis of the sawtooth wave current for horizontal deflection supplied to the horizontal deflection coil changes at a constant rate on the time axis. In this case, the electron beam of the picture tube is deflected so that the deflection angle per unit time becomes a constant angle α as illustrated in FIG.

On the other hand, since the image display surface of the picture tube is curved with a large radius of curvature so that it is as close to a flat surface as possible, the distance from the deflection center of the picture tube to the image display surface is not constant. When the deflection angle of the electron beam per unit time is constant as described above, the moving distance of the electron beam per unit time on the image display surface is the peripheral area illustrated by Q' in FIG. Since the movement distance at is larger than the movement distance Q at the center, even if an attempt is made to project an image with a constant grid interval pattern on the image display surface, the image actually displayed on the image display surface will be As illustrated in FIG. 8, the image becomes such that the peripheral area is elongated compared to the central area.

In order to solve the above problem, conventionally, as shown in FIG. A so-called figure-eight correction capacitor 3 was connected, which also served as a blocker.

That is, by appropriately adjusting the resonance period between the figure-8 correction capacitor 3 and the horizontal deflection coil 2, the sawtooth wave current for horizontal deflection can be adjusted to the center as shown by the dotted line in FIG. The slope is steep at one end and gentle at both ends to avoid the above-mentioned problems.

(Problems to be Solved by the Invention) The conventional method using the figure-8 correction capacitor 3 described above corrects the waveform of the horizontal deflection current by utilizing the resonance between the figure-8 correction capacitor 3 and the horizontal deflection coil. Therefore, good correction can be made when the horizontal deflection frequency is constant, but when the horizontal deflection frequency is switched to multiple levels, it is difficult to For example, as shown in Figure 10, a plurality of 8
(Figure 10 is a configuration example where two horizontal deflection frequencies are switched)
It is necessary to switch by the changeover switch 4.

However, since a large current flows through the figure-8 capacitor, the changeover switch 4 is likely to generate an arc between the contacts each time the current is connected or disconnected. Therefore, in order to switch the changeover switch 4 safely and reliably, Complicated operations are required, such as the need to switch the changeover switch 4 while the power to the device is turned off, and the linearity of only a portion of the image, for example, the left edge of the image, cannot be changed. The problem was that even if there was a request for slight changes, it could not be easily accommodated.

(Means for Solving the Problems) The present invention includes one permanent magnet and two pairs of permanent magnets arranged in such a manner that the magnetic flux generated by the permanent magnet can be circulated in series. The above two saturable magnetic cores are provided with two saturable magnetic cores that are respectively in contact with the magnetic poles and are spaced apart from each other, and windings that are respectively wound around the two saturable magnetic cores. When the windings respectively wound around the magnetic cores are connected in series and a current is passed through them in a fixed direction, the magnetic flux generated by the windings respectively wound around the two saturable magnetic cores is The saturable magnetic core is wound around the two saturable magnetic cores so that the magnetic flux generated by the permanent magnet is added to the magnetic flux generated by the permanent magnet, and the magnetic flux generated by the permanent magnet is subtracted from the magnetic flux generated by the permanent magnet in the other saturable magnetic core. The present invention provides a horizontal deflection linearity correction device in which 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.

(Example) Hereinafter, specific contents of the horizontal deflection linearity correction device of the present invention will be explained in detail with reference to the accompanying drawings. 1 to 3 are diagrams showing the structure of an embodiment of the container of the horizontal deflection linearity correction device of the present invention.

Further, FIG. 4 is a block diagram of a horizontal deflection linearity correction circuit using the horizontal deflection linearity correction device of the present invention.

In Fig. 4, 1 is a horizontal deflection output circuit, 2 is a horizontal deflection coil, and LCA is the horizontal deflection linearity correction device of the present invention. Terminals c and d are connected to the horizontal deflection linearity correction device LC shown in FIGS. 1 to 3, respectively.
They respectively correspond to the terminal C2d in A.

Reference numeral 5 in Fig. 4 is a capacitor for blocking DC component,
The capacitance value of this capacitor 5 is selected to be large so that its impedance is sufficiently small at the frequency of the horizontal deflection 'a1 applied to the horizontal deflection coil 2. That is, in the circuit arrangement shown in FIG. 4, 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 horizontal deflection linearity correction table is corrected by LCA.

Now, in the horizontal deflection linearity correction device of the present invention shown in FIGS. 1 to 3, 7 and 8 are drum cores made of ferrite, which is a ferromagnetic material having saturable magnetic properties. 9 is a permanent magnet, and 10.11 is a winding wound around the drum core 7.8.

The drum core 7.8 described above is arranged in such a manner that the magnetic flux generated by one permanent magnet 9 can be circulated in series, and is in individual contact with the two magnetic poles N and S forming a pair in the permanent magnet 9, The windings 10.8 are provided at the front corners of each other and are respectively wound around the two drum cores 7.8. +1 are connected in series.

The connection polarity of the two windings 10.11 respectively wound around the two drum cores 7.8 described above causes a current i to flow in a fixed direction through the two windings 7 and 8 connected in series. When the magnetic flux φ generated at 10.11 in each of the windings respectively wound around the two drum cores 7.8 is
1. It is determined that φ2 is added to the magnetic flux φ3 caused by the permanent magnet 9 described above for one tram core 7, and subtracted from the magnetic flux φ3 generated by the permanent magnet 9 for the other drum core 8 (described above). If the direction of the constant current i flowing through the two windings 7 and 8 connected in series is opposite to the above, IDI 2.
Magnetic flux φl is generated at 10.11 in each winding wound around two drum cores 7.8.

φ2 is the magnetic flux φ1 of one drum core 7.
and the magnetic flux φ3 caused by the permanent magnet 9, and for the other drum core 8, it is added between its magnetic flux φ2 and the magnetic flux φ3 caused by the permanent magnet 9).

In the horizontal deflection linearity correction device shown in FIGS. 1 to 3, any of the embodiments is
The magnetic flux φ3 generated from the permanent magnets 9 is made to circulate in series to the two drum cores 7.8, and the magnetic flux φ1 generated by the current i flowing through the winding 10 wound around the drum core 7 is In order to prevent the magnetic flux φ2 generated by the current i flowing through the winding 11 wound around the drum core 8 from flowing back into the drum core 7, the magnetic flux φ2 is prevented from flowing back into the drum core 7.

Therefore, the winding 1 wound around the drum core 7 described above
The inductance LIO of 0 and the inductance Lll of the winding 1t211 wound around the drum core 8 change as shown by the curves LIO and Lll in FIG. Changes to

That is, when ff1Ai flowing through the winding 10 is positive, the inductance of the winding 10 wound around the drum core 7 becomes saturated as the current i increases. Winding 1
The inductance LIO of 0 is equal to the current i flowing through the winding 10.
As the current i increases, the drum core 7 decreases, and if the current i flowing through the winding 10 is negative,
Since the magnetic flux density inside decreases, the inductance LIO of the winding 10 wound around the drum core 7 becomes 1 turn f.
It increases as the current i flowing through ilO increases.

On the other hand, the inductance of the 4% winding 11 wound around the drum core 8 is such that when the current i flowing through the winding 11 is negative, the drum core 8 becomes saturated as the current i increases. The inductance Lit of the winding 11 decreases as the current i flowing through the winding 11 increases, and if the current i flowing through the first winding 11 is positive, the drum core decreases as the current i increases. Since the magnetic flux density in the drum core 8 decreases, the inductance Lll of the winding tfill wound around the drum core 8 is: g1
It increases as the current l flowing through 7111 increases.

Therefore, the series inductance of the two windings 7 and 8, that is, the inductance L(io+11) between the terminals c and d in the horizontal deflection linearity correction device, is the fifth
As shown in the curve L (10+11) in FIG. 5, which is a composite of the song ILIO and the curve Lll in the figure, 1!
The inductance is the minimum at the point where the current i is zero, and increases as the current increases regardless of whether the current i is positive or negative.

Hence the horizontal deflection linearity corrector! Terminal c of LcA
, d, when a sawtooth wave current i as shown in the lower part of FIG. 5 is applied to the horizontal deflection linearity correction device L.
The inductance value between terminals c and d of CA changes so that it becomes the largest corresponding to the positive and negative peak values of the sawtooth wave current, and becomes the smallest at the center.

Therefore, in the horizontal deflection linearity correction circuit shown in FIG. 4, in which the horizontal deflection linearity correction device fi LCA of the present invention as shown in FIGS. The sawtooth wave current flowing through the horizontal deflection coil 2 has a slope that is gentler at the beginning and end of the sawtooth wave, as shown by the dotted line curve ab in FIG. By using the horizontal deflection linearity correction device CA, it is possible to effectively prevent the occurrence of image distortion as shown in FIG.

(Effects) As is clear from the detailed explanation above, the horizontal deflection linearity correction device of the present invention can serially circulate the magnetic flux generated by one permanent magnet and the permanent magnet. Two saturable magnetic cores that are arranged in such an arrangement manner that they are respectively in contact with the two magnetic poles forming a pair of permanent magnets and are spaced apart from each other; When the windings respectively wound around the two saturable magnetic cores are connected in series and a current is passed in a certain direction, the windings are wound around the two saturable magnetic cores respectively. The magnetic flux generated by each of the windings is added to the magnetic flux caused by the permanent magnet in one saturable magnetic core, and subtracted from the magnetic flux caused by the permanent magnet in the other saturable magnetic core. Horizontal deflection linearity obtained by determining the connection polarity of two windings wound around two saturable magnetic cores, and connecting the series-connected windings substantially in series with the horizontal deflection coil of the picture tube. The horizontal deflection linearity corrector of the present invention does not utilize resonance between a horizontal deflection coil and a capacitor, but is proportional to the horizontal deflection current, regardless of changes in the frequency of the current. Since the inductance of the winding wound around the saturable magnetic core is changed by the magnetic flux generated by In the horizontal deflection linearity correction device of the present invention, the mode of correction of the waveform of the horizontal deflection current can be arbitrarily changed by adjusting the number of turns of the windings 11A10.11 individually wound around the drum core 7.8. Therefore, for example, it is easy to fine-tune the horizontal linearity in the left and right portions of the screen independently.Furthermore, the horizontal deflection linearity correction device of the present invention
Although it is possible to fine-tune the horizontal iI linearity in the left and right portions of the screen independently as described above, only one permanent magnet is required for its construction, and it is possible to independently finely adjust the horizontal iI linearity in the left and right portions of the screen. Since the two windings connected in series can be connected in series to form two terminals and can be constructed as one component together with one permanent magnet, the horizontal deflection linearity correction device can be constructed at low cost and compact.

[Brief explanation of the drawing]

1 to 3 are block diagrams of embodiments of the horizontal deflection linearity correction device of the present invention, and FIG. 4 is a diagram of a horizontal deflection linearity correction circuit using the horizontal deflection linearity correction device of the present invention. Block diagram, Figure 5 is an example of a characteristic curve, Figure 6 is a waveform diagram of a sawtooth current, Figure 7 is an illustration of problems in a wide deflection angle picture tube, and Figure 8 is an illustration of image distortion. , FIG. 9, and FIG. 10 are circuit diagrams of conventional examples. 1...Horizontal deflection output circuit, 2...Horizontal deflection coil, 3
...Character 8 correction capacitor, 5...Capacitor, 7°8...Drum core, 9...Permanent magnet, 10.11.
...Winding, LCA...Horizontal deflection linearity correction device, patent applicant: Victor Company of Japan. Agent Patent Attorney Takao Imama

Claims (1)

[Claims] A state in which one permanent magnet and two magnetic poles forming a pair of the permanent magnet are individually contacted and separated from each other in an arrangement such that the magnetic flux generated by the permanent magnet can be circulated in series. and windings respectively wound around the two saturable magnetic cores, and the windings respectively wound around the two saturable magnetic cores are connected in series. , when a current in a certain direction is passed through it, the magnetic flux generated by each winding wound around the two saturable magnetic cores is added to the magnetic flux caused by the permanent magnet for one saturable magnetic core, and the magnetic flux generated by the permanent magnet is added to the magnetic flux for one saturable magnetic core, and 2 is wound around the two saturable magnetic cores so as to be subtracted from the magnetic flux by the permanent magnet in the saturable magnetic core
A horizontal deflection linearity correction device comprising: determining the connection polarity of the two windings; and substantially connecting the series-connected windings in series with the horizontal deflection coil of the picture tube.