JPH0488788A - Mis-convergence correction device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Use The present invention relates to a misconvergence correction device, and is applicable to, for example, correcting misconvergence of an electron beam of an in-line color cathode ray tube. In the misconvergence correction device, by rotatably attaching a magnet that applies a bias magnetic flux to the core, the strength of the bias magnetic flux passing through the core can be freely set by rotating the magnet. This allows fine adjustment of the composite magnetic flux of the magnetic flux generated by the first and second auxiliary coils wound around the core and the bias magnetic flux, and as a result, the distribution of the deflection magnetic field generated by the first and second main coils can be adjusted. This allows for fine adjustments.

C. Conventional technology Conventional misconvergence, which is a color shift caused by three electron beams not passing through the same hole in the shadow mask at the same time due to the rotation of the electron gun of a cathode ray tube, is called vertical misconvergence on the X-axis. There is something called.

As shown in FIG. 6, such X-axis bow-shaped vertical misconvergence is such that the scanning lines RR and BB of the red beam R and blue beam B are distorted in opposite directions from the horizontal direction at the periphery of the cathode ray tube surface. be.

In order to correct this bow-shaped vertical misconvergence, sub-coils 3 and 4 for correction are connected in series as shown in Fig. 8 to saddle-shaped deflection coils 1 and 2 (Fig. 7), which are conventionally connected in parallel. 3 and 4 are wound around a core, and a means for applying a bias magnetic flux to the core is provided, thereby adjusting the distribution of the deflection magnetic field generated in the deflection coils 1 and 2 when the screen is scanned left and right. (Japanese Unexamined Patent Publication No. 158534/1983).

Furthermore, it has been proposed to adjust the correction magnetic field generated in the convergence correction coil by connecting a saturable reactor to a pair of convergence correction coils wound around a convergence yoke (Japanese Patent Laid-Open No. 61-269
No. 835 and Japanese Unexamined Patent Publication No. 61-269836).

Misconvergence correction device using saturable reactor 5
As shown in FIG. 9, the U-shaped core 6 has magnetic legs 6A and 6B.

A coil bobbin 8 around which a subcoil 7 is wound is attached to the upper magnet 116A, and the lower magnet 116
A coil bobbin 10 around which a subcoil 9 is wound is attached to B.

A T-shaped core 11 is disposed in the U-shaped core 6 via magnets 12 and 13, facing the magnets 116A and 6B.

Here, coil bobbins 8 and 10 are coil bobbins 8 and 1.
The magnets 12 and 13 provide bias magnetic fluxes φ (indicated by broken line arrows) to the subcoils 7 and 9 wound with zero windings so that the directions thereof are opposite to each other.

As a result, when current flows in the same direction in the subcoils 7 and 9, the direction of the magnetic flux φC generated in the coils is the same direction with respect to the bias magnetic flux φA from the magnets 12 and 13, and the other direction is opposite. It is designed to generate a magnetic flux of

As a result, the impedance of the subcoils 7 and 9 changes, and the current flowing through the convergence correction coil is varied, so that a magnetic field that corrects misconvergence is generated.

Problem to be Solved by the Invention When trying to correct the misconvergence caused on the screen by the misconvergence correction device 5, the bias magnetic flux φ given to the subcoils 7 and 9
, when it is desired to adjust the strength of the coil bobbins 8 and 10, the U-shaped core 6 is attached to or separated from the magnets 12 and 13, and the attachment of the coil bobbins 8 and 10 is adjusted by shifting the position of the coil bobbins 8 and 10 to the left and right. However, depending on this method, it is difficult to adjust the magnetic field, and misconvergence cannot be finely adjusted, and screws must be adjusted at two locations for correction, making adjustment time-consuming.

Also, if the vertical relationship between the red beam R and the blue beam B of the bow-shaped vertical misconvergence is reversed, it is necessary to change the direction of the magnetic rods of the magnets 12 and 13 fixed to the T-shaped core 11 to be opposite. However, there is a problem in that the adjustment time during assembly of the misconvergence correction device increases.

The present invention has been made in consideration of the above points, and allows for easy bow-type vertical misconvergence with a simple configuration. This paper attempts to propose a misconvergence correction device that can adjust Ii.

Means for Solving Problem 211 In order to solve this problem, in the present invention, first and second auxiliary coils 22 and 211 are connected in series to first and second main coils 1 and 2, respectively, which are connected in parallel. 23 is wound around the core 21, and the core 21 is given a predetermined bias magnetic flux φN by a magnet 26. In this convergence correction device, a magnet 26 that gives a predetermined bias magnetic flux φ9 to the core 21 is rotatably attached to the core 21. do it like this.

F action When it is desired to maximize the bias magnetic flux φ8 given to the magnetic legs 2LA and 21B of the core 21 around which the first auxiliary coil 22 and the second auxiliary coil 23 are wound, the magnet 26
The magnet 26 is arranged so that the magnetic poles N and S of the magnet 1j21A and 21B face each other, and when it is desired to minimize the bias magnetic flux φ, the magnet 26 is rotated so that 1 mN and S of the magnet 26 and the magnetic leg 21A and 21B are arranged in a position where they are not perpendicular to each other and you want to adjust the bias magnetic flux φ to the desired strength, rotate the magnet 26 to the desired position and align the magnetic poles N and S of the magnet 26. 1121A
By adjusting the relative position between the main coils 1 and 21B, the correction amount of the deflection magnetic field φ generated in the first and second main coils 1 and 2 can be arbitrarily set, and the bow-shaped vertical misconvergence of the electron beam can be easily fine-tuned. can do.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, 20 indicates a misconvergence correction device as a whole, and magnetic legs 21A and 2 of a U-shaped core 21 are shown.
Coil bobbins 24 and 25 around which subcoils 22 and 23 are wound are attached to 1B.

Here, the subcoils 22 and 23 are the deflection coils 1 and 2 of the deflection yoke connected in parallel, similar to the connection shown in FIG.
are connected in series.

In the U-shaped core 21, a disc-shaped magnet 26 having an N pole and an S pole on the peripheral edge so as to face the magnetic JIs 21A and 21B is rotatable about a shaft (not shown) on the center line 1. It is installed. The magnet 26 is a permanent magnet, and its attachment position can be freely changed around the center line l, thereby making it possible to change the bias magnetic flux φ passing through the magnetic legs 21A and 21B formed by winding the subcoils 22 and 23. It has been made possible.

Further, the coil bobbins 24 and 25 are attached so that the directions of bias magnetic fluxes φi for the subcoils 22 and 23 wound around the coil bobbins 24 and 25 are opposite to each other.

Furthermore, currents in opposite directions flow through the subcoils 22 and 23 when the electron beam is deflected to the left and to the right, respectively.

In the above configuration, if the magnet 26 is arranged so that the N and S poles face the subcoils 22 and 23, respectively, as shown by the broken line in FIG. 2, then the bias magnetic flux φ passing through the subcoils 22 and 23 ,(
) is maximized.

In this state, as shown by the solid line in the first rg, a bias magnetic flux φ is generated in the subcoil 22 wound around the coil bobbin 24.
, magnetic flux φ in the same direction as . A bias magnetic flux φ is generated in the subcoil 23 wound around the coil bobbin 25, and a magnetic flux φ in the opposite direction. , the inductance of the coil decreases as the passing magnetic flux increases, so that the inductance of the upper subcoil 22 decreases to L21 (Figure 3), while the inductance of the lower subcoil 25 decreases to Lll (Figure 3). Figure 3).

As a result, the inductance of the upper sub-coil 22 and the deflection coil l becomes lower than that of the lower sub-coil 23 and the deflection coil 2.
The current flowing through the deflection coil 1 side increases, and the current flowing through the lower deflection coil 2 side decreases, causing the center of the deflection magnetic field φ to become smaller than the inductance of the deflection coil 1.
and deviates upward from the center position of 2 (Fig. 4).

As a result, a horizontal magnetic field is generated at the central position of the deflection coils 1 and 2, and a force that moves the red beam R downward is generated.
Also, a force is generated that moves the blue beam B upward.

On the other hand, when the right side of the screen is deflected, the deflection currents flowing through the subcoils 22 and 23 are also reversed, so the currents flowing through the upper subcoil 22 and the deflection coil 1 decrease, while the lower subcoils 23 and 23 decrease. Deflection coil 2
The current flowing through the deflection coils 1 and 2 increases, and the center of the deflection magnetic field φ is biased below the center position of the deflection coils 1 and 2 (FIG. 5).

In addition, as the deflection current increases as the screen is deflected to the left and right, the force that moves the red and blue beams R and B downward and upward increases (as a result, the bow-shaped vertical misconvergence shown in Figure 6 is corrected). .

On the other hand, when you want to finely adjust the amount of correction for the red beam R and blue beam W by the misconvergence correction device 20, move the magnet 26 from the position shown by the broken line in FIG. As the sub-coils 22 and 23 are rotated clockwise as shown, the magnetic flux φ passing through the sub-coils 22 and 23 gradually decreases.

As a result, a composite magnetic flux φi+φ is generated within the subcoils 22 and 23. and φ8−φ decrease, and the current flowing through the upper subcoil 22 and deflection coil 1 gradually decreases, whereas the current flowing through the lower subcoil 23 and deflection coil 2 decreases.
The current flowing through the sides gradually increases, and the center of the deflection magnetic field φ generated between the deflection coils 1 and 2 gradually moves from the center position of the deflection coils 1 and 2.

Furthermore, when the magnet 26 is rotated clockwise to the position shown by the solid line (that is, the position perpendicular to the magnetic legs 21A and 21B of the U-shaped core 21), the subcoils 22 and 2
The bias magnetic flux −0 transmitted through the subcoils 22 and 23 becomes equal, and the absolute values of the inductances L1 and L2 of the subcoils 22 and 23 change but become equal.

As a result, substantially equal currents flow through the deflection coils 1 and 2, and the center of the deflection magnetic field φ generated by the deflection coils 1 and 2 substantially coincides with the center position of the deflection coils 1 and 2.

According to the above configuration, the center position of the deflection magnetic field φ generated by the deflection coils 1 and 2 when deflecting the red and blue beams R and B in the left and right directions is above and below the center position of the deflection coils 1 and 2. The amount of deviation in this direction can be freely set according to the amount of rotation of the magnet 26. This makes it possible to finely adjust the misconvergence of the electron beam more easily than in the past.

Also, the bias magnetic flux φ passing through the subcoils 22 and 23
Since the strength of A can be finely adjusted at the same time, it is possible to reduce the deterioration in focus that conventionally occurs when the coil bobbins 8 and 10 around which the sub-coils 7 and 9 are wound are individually moved.

In addition, in the above-mentioned embodiment, the case where the magnet 26 is rotated 90 degrees clockwise from the position where the sub-coils 22 and 23 and the N pole and the S & The magnet 26 may be rotated to a position where the N pole and S bridge of the magnet 26 face the subcoils 23 and 22, respectively.

If this is done, the bias magnetic flux φ given to the subcoils 22 and 23 will be opposite to that in the above embodiment, and the vertical relationship between the red beam R and the blue beam B will be reversed. It can be used for fine adjustment when the magnet is turned upside down, and there is no need to reverse the direction of the magnet and reinstall it as in the conventional case.

In addition, in the above embodiment, Nff1 and S
Although the case has been described in which the disk-shaped magnet 26 having a rod is used, the present invention is not limited thereto, and can be applied to stacked-shaped magnets such as rod-shaped magnets.

Further, in the above-described embodiment, a case was described in which a permanent magnet was used as the magnet 26, but the present invention is not limited to this, and an electromagnet may also be used.

Effects of the Invention As described above, according to the present invention, the magnet is attached to the core so that the strength of the bias magnetic flux passing through the core around which the first and second auxiliary coils are wound can be arbitrarily set. By attaching it so that it can rotate freely, the correction amount of the deflection magnetic field generated by the main coil can be freely adjusted, and the distribution of the deflection magnetic field generated on the left and right sides of the screen can be easily fine-tuned. It is possible to correct bow-shaped vertical misconvergence.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the misconvergence correction device according to the present invention, FIG. 2 is a route diagram for explaining its operation, and FIG. 3 is a diagram for explaining the composite magnetic flux and inductance generated in the subcoil. FIGS. 4 and 5 are route maps for explaining the deflection magnetic field generated in the deflection coil, and FIG. 6 is a route map for explaining the bow-shaped vertical misconvergence.
FIG. 7 is a plan view for explaining the deflection yoke, FIG. 8 is a connection diagram showing the connection between the deflection coil and the auxiliary coil, and FIG. 9 is a plan view showing a conventional convergence correction device. 12.2...Deflection coil, 3.4.22.23
...Subcoil, 21 ...Core, 24
, 25... Coil bobbin, 26... Magnet.

Claims (1)

[Claims] First and second auxiliary coils connected in series to first and second main coils connected in parallel are wound around the core,
A misconvergence correction device in which a predetermined bias magnetic flux is applied to the core by a magnet, characterized in that the magnet for applying a predetermined bias magnetic flux to the core is rotatably attached to the core.