JPS6292595A - Error convergence correcting device - Google Patents

Abstract

PURPOSE:To simultaneously correct a frame aberration and a G sagging by inputting and distributing the horizontal deflecting electric current to a pair of the saturable inductance, inputting the electric current to a differential transformer, removing the difference electric current, and providing a pair of the auxiliary coils to the rear edge part of the deflecting yoke. CONSTITUTION:To one side terminal of a vertical deflecting coil 7, auxiliary coils 3A-3C and 4A-4C to generate a 6-pole magnetic field are connected, to the tip, coils 1A and 1A' are connected which give the direct current bias to saturable inductors 1B and 1C, and a vertical deflecting electric current Iv is inputted. To one side terminal of a horizontal deflecting coil 8, a pair of the coil connected in parallel is connected, and a horizontal deflecting electric current Ih is inputted. To a coil 2C to remove the electric current differentially, auxiliary coils 5A-5C and 6A-6C to generate the 6-pole magnetic field are connected. The inductor 1B and the coil 1A constitute a magnetic circuit 1, the inductor 1C and the coil 1A' constitute a magnetic circuit 1' and coils 2A-2C constitute a differential transformer 2. Thus, the frame aberration and a G sagging of the in-line type color Braun tube 16 can be corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a convergence correction device for an in-line color cathode ray tube.

[Background of the invention]

In recent years, there has been a demand for higher definition in color display devices, but the occurrence of misconvergence in color display devices is a cause of deterioration in image quality.

For example, in an in-line color cathode ray tube,
In order to cause each of the red (R), green (G) and blue (B) beams to self-converge even when the beams are in their normal positions relative to the tube, the horizontal deflection magnetic field is changed to the bin magnetic field. , the vertical deflection magnetic field is a barrel magnetic field. For this reason, during horizontal deflection.

Misconvergence (hereinafter referred to as "misconvergence") occurs when the deflection amount of the side and one beam (R, B beam) rasters is different from the deflection amount of the center beam (G beam) raster during vertical deflection.

(referred to as coma aberration) occurs.

Conventionally, such coma aberration was corrected on the CRT side by installing a magnetic field control element in the Fraun tube. This may cause new problems such as changes in coma aberration.

Furthermore, in Japanese Patent Publication No. 51-4815, as an example of a device for correcting misconvergence, a device for correcting side beam raster misconvergence is described. Correction of misconvergence with raster, in other words n
No consideration was given to correction of #-i coma aberration.

In addition, in the above-mentioned method of correcting by providing a magnetic field control element in the cathode ray tube, the so-called G coma aberration increases at the corner of the screen, as shown in FIG. 8, which will be described later.
No consideration was given to corrections for this.

[Purpose of the invention]

The purpose of the present invention is to solve the problems of the prior art as described above, and
It is an object of the present invention to provide a misconvergence correction device capable of simultaneously correcting coma aberration and Gt'L.

[Summary of the invention]

In order to achieve the above object, the present invention inputs 11 horizontal deflection currents into a pair of saturable inductors whose inductances vary differentially in the horizontal and vertical deflection periods, divides the current into two currents, and further divides the horizontal deflection current into two currents. The distributed nf7:, tc current is input to a differential transformer and a current proportional to the difference is taken out, and two sets of auxiliary coils are installed at the rear end of the deflection yoke to generate a six-pole foundation field. is a full wave vertical deflection current,
The other set is constructed so that the current extracted from the transformer flows therethrough, that is, the correction is performed not on the cathode ray tube side as in the conventional case, but on the deflection yoke side.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

In FIG. 1, one terminal of the vertical deflection coil 7 has a
Auxiliary coil 68~5C, 4~4 that generates a 6-pole magnetic field
C is connected to n, and beyond that is a saturable inductor IB,
Coils IA' and IA for applying a DC bias to the IC are connected to each other, and further connected to a terminal 9 to which a vertical deflection current IV from a vertical deflection current supply source is input. Further, one terminal of the horizontal deflection coil 8 is connected to a pair of coils connected in parallel (a coil in which a saturable inductor 1B and two coils for differentially extracting current are connected in series, and a saturable A coil in which an inductor 1C and a coil 2B are connected in series is connected, and the end thereof is connected to a terminal 10 to which a horizontal deflection current 8 from a horizontal deflection current supply source is input. In addition, the coil 2C for differentially extracting current includes auxiliary coils 5A to 5C that generate a six-pole magnetic field.
, 6A to 6C are connected. Note that the saturable inductor 1B and one coil constitute a magnetic circuit 1, and the saturable inductor 1C and coil IA' constitute a magnetic circuit 1'. 1. Coils 2A, 2B, and 2C constitute a differential transformer 2.

FIG. 2 is an explanatory diagram for explaining the entire configuration of the saturable inductor shown in FIG. 1.

As shown in FIG.
B, IC and coils IA and IA' for applying a DC bias (perpendicular deflection current) are wound one pair each.

FIG. 6 shows the configuration of the differential transformer shown in FIG. 1, which differentially extracts the 'I!' current. - It is an explanatory diagram for explanation.

As shown in FIG. 6, the core 13 is composed of a Troutal type core, and the core 16 is equipped with a coil 2A.

2B'? I: The winding force and current direction are determined and wound so that magnetic fluxes in opposite directions are generated, and the coil 20 is further wound to form #+.

FIG. 4 is a rough explanatory diagram illustrating the configuration of the auxiliary coil shown in FIG. 1.

As shown in FIG. 4, the core 14.15 is composed of an E-shaped core, and the legs of the core 14 are provided with auxiliary coils 3A-3G, 5A.
~5C, and auxiliary coils 4A~4C9 are attached to the legs of the core 15.
6A to 6C are each arranged in a winding manner.

Next, we will explain the operation of the misconvergence correction device configured as described above.When coma aberration occurs in the upper and lower metal bodies of the screen (mainly the upper and lower coma aberration correction provided in the electron gun on the cathode ray tube side) When the magnetic field control element for the electron beam is removed), the raster on the screen becomes K as shown in Figure 5.On the other hand, if a hexapole magnetic field as shown in Figure 6 is generated near the cathode ray tube electron gun,
The R and B beams are deflected downward, and as shown in FIG. 7, the HR and B beam rasters move downward relative to the G beam raster on the screen. Therefore, as can be seen from this, if the hexapole output field is changed in a vertical period and the R and B beams are deflected downward in the upper half of the screen and upward in the lower half of the screen, the screen Even vertical coma can be corrected. Therefore, in this embodiment, as shown in FIG.
~4C is the rear end of the deflection yoke on the electron gun side (Brown FF1
6), and its auxiliary coils 38 to 3C
.

The above-mentioned coma aberration is corrected by flowing a vertical deflection current IV to 48 to 4C as shown in FIG.

As shown in FIG. 8, the raster after comatic aberration correction is a pattern in which Gd f'L remains at the corner of the screen.Next, a method for correcting Gdn will be explained.

As described above, when a six-pole magnetic field is generated, the R and B beam rasters move upward or downward relative to the G beam raster. Therefore, by emphasizing only the corners of the screen, Gdn as shown in FIG. 8 can be corrected. That is, in order to make the R and B beams more uniform at the corner of the screen due to the hexapole fundamental field, the desired current is fully applied to the auxiliary coils 5A to 5C and 6A to 6C shown in FIG. It's funny. In this embodiment, the saturation inductors IB and IC and the differential transformer 2 described above are used for this purpose.

First, the operation of the saturable inductor 113°1C will be explained using FIG. The following example shows that when the horizontal deflection is to the right of the center of the screen (I, > 0) and the vertical deflection is above the center of the screen (IV > 0), the current flows in the direction shown in Figure 2. deceive In FIG. 2, the inductance L of the saturable inductor 1B.

is the horizontal deflection, and the magnetic flux φ1. produced by the vertical deflection current Iy. When φ is in the same direction, p decreases as the core 11 becomes magnetically saturated. Contrary to the above, the inductance L2 of the saturable inductor 1C increases because the magnetic fluxes φ2 and I9 cancel each other out, and the magnetic saturation of the core 12 decreases. As a result, the horizontal deflection current I, , I2 becomes I,>I. Saturable inductor IB, IC inductance L, , L2
FIG. 9K shows the change in the vertical deflection period TV, and FIG. 10 shows the change in the horizontal deflection period T8.

Next, f'Lfc horizontal deflection current I, obtained in this way,
I2 flows n through the differential transformer 2 shown in FIG. 3, and the relationship between the currents is as shown in FIG. 11. In Fig. 5, the horizontal deflection current ■□〉0. Vertical deflection periodic work.

>0, the horizontal deflection current is 1. ．． The relationship between I and I is
＞12, therefore, the relationship between the magnetic flux φ generated by φ and the magnetic flux φB generated by I2 is φ, 〉I8
Therefore, the magnetic flux of φ<'H remains in the direction of φ, and current flows in the direction of the arrow in the coil 2C. [ζHorizontal deflection current <0. Vertical deflection current I
When v>0, as shown in Fig. 10, the relationship between the horizontal deflection currents I,, I, becomes I<5, and the magnitude relationship is reversed, but in Fig. 5, I,, I, Since the direction of the current is also reversed (II! < 0), coil 2CK flows in the direction of the arrow as in the previous case.

will flow. In other words, as shown in FIG. 11, the current flow of the coil 2C can be made in proportion to the horizontal deflection current I and in the same direction regardless of the horizontal deflection direction.
Therefore, this vL flow I is determined by the auxiliary coil 5 shown in FIG.
By flowing the signals to A to 5C and 6A to 6C, it becomes possible to correct G and t at the upper corner of the screen. Also, if the vertical deflection coil is <00, the horizontal deflection is 1!, as shown in FIG. The relationship between flow I,, I, is
〉0 is reversed, so Figures 3 and 11
The direction of the output current of coil 2C in the figure is 〉0
It can be seen that the direction is opposite to that of . Therefore, this
This makes it possible to correct Gdn even at the lower corner of the screen.

〔Effect of the invention〕

As described above, according to the present invention, the coma aberration in the entire upper and lower parts of the screen and the G density in the corners of the screen can be corrected at the same time. A high-resolution image with completely overlapping images is obtained.

In addition, by fully adjusting the current flowing through the auxiliary coil, it is possible to set a free amount of correction for coma aberration and G72n, and therefore, even if there are manufacturing variations in the deflection yoke, it can be absorbed. It is also possible to absorb variations when combining a deflection yoke and a cathode ray tube.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, and Fig. 2 is a circuit diagram showing an embodiment of the present invention.
An explanatory diagram for explaining the configuration of the saturable inductor shown in the figure,
Figure 3 is an explanatory diagram to explain the configuration of the differential transformer, Figure 4 is a companion diagram to explain the configuration of the auxiliary coil, and Figure 5 is displayed at the top and bottom of the screen as misconvergence. A schematic diagram showing the occurrence of coma aberration and G-Dn at the corner. Figure 6 is a schematic diagram showing the relationship between the hexapole magnetic field and the electron beam. Figure 7 shows the side beam caused by the hexapole magnetic field in Figure 6. A schematic diagram showing how Rasuf moves and the situation, Figure 8 is a schematic diagram showing how corner N5KG f occurs as a misconvergence, Figures 9 and 10 are the same.
FIG. 11 is a ninth explanatory diagram for explaining the current change in the differential transformer of FIG. 3. FIG. Symbol explanation 1B, IC...Saturable inductor, 2...Differential transformer, 3A~5C, 4A~4C, 5A~5C16A~
6C...Auxiliary coil, 7...Horizontal deflection coil, 8.
・Vertical deflection coil, 11.12...CI type cocoa 15
...Toroidal core, 14.15...E-shaped core, 16...Cathode ray tube.

Claims (1)

[Claims] 1) In a color display device having an in-line color cathode ray tube, a pair of saturable inductors whose inductances change in a certain relationship in horizontal and vertical deflection periods, and currents input to the first and second coils. and a transformer that outputs a current proportional to the difference between the third coil and the horizontal deflection current to the intersection where the ends of the pair of saturable inductors are connected to each other to adjust the inductance ratio of the saturable inductors. The deflection current is divided into two currents based on the current, one of the divided currents is applied to the first coil of the transformer, and the other current is applied to the second coil of the transformer.
In addition, first and second auxiliary coils are respectively provided near the electron gun in the color cathode ray tube to generate a six-pole magnetic field. An output current taken out from the third coil of the transformer is passed through the auxiliary coil,
A misconvergence correction device characterized in that a vertical deflection current is passed through the second auxiliary coil to apply a correction magnetic field to the color cathode ray tube to correct misconvergence in the color cathode ray tube.