JPH0448621Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of a dynamic convergence correction device for a three-electron gun in-line color cathode ray tube.

<Prior art> As is well known, in three-electron gun in-line color cathode ray tubes, various types of misconvergence occur due to tolerances of each component during manufacturing, so the horizontal deflection magnetic field of the deflection yoke is The vertical deflection magnetic field is a barrel-shaped magnetic field to reduce misconvergence. However, it is very difficult to eliminate misconvergence by controlling and adjusting the deflection magnetic field alone, so in the past, dynamic convergence correction coils were connected to the horizontal and vertical deflection coils to control the impedance of the deflection yoke. By doing so, the occurrence of misconvergence is suppressed as much as possible.

Conventionally, this type of dynamic convergence correction device has a control coil 11 arranged in the center, and a pair of controlled coils (impedance coils) 12 and 13 on both sides, as shown in FIG.
It has a configuration with . Each controlled coil 1
2 and 13 are divided into two parts 12a, 12b and 13a, 13b, respectively, and one controlled coil 1
2a, 12b are a pair of drum-shaped cores 14a, which are arranged in parallel on the left side of the control coil 11 in the figure.
14b, and the other controlled coil 13a, 13
b is another pair of drum-shaped cores 15a and 15b arranged in parallel on the right side of the control coil 11;
Each is wrapped. Each pair of drum-shaped cores 1
4a, 14b and 15a, 15b have magnets 1 magnetized in the thickness direction on their outer surfaces.
6 and 17 are attached to provide magnetic bias to the controlled coils 12 and 13.

The dynamic convergence correction device configured as described above is electrically connected to each deflection coil of the deflection yoke, as shown in FIG. 3, for example. That is, the control coil 11 is a pair of vertical deflection coils 18
The vertical deflection current _Iv is supplied from the vertical deflection circuit 19. On the other hand, controlled coil 1
2 and 13, one of which 12 is connected in series with one horizontal deflection coil 20 disposed above the deflection yoke, and the other 13 is connected in series with the other horizontal deflection coil 21 disposed below the deflection yoke. A horizontal deflection current I _H is supplied from the horizontal deflection circuit 22 .

It is well known that misconvergence can be corrected by the dynamic convergence correction device configured as described above, so a description of its operation will be omitted. ,21
It is necessary that the horizontal deflection current flowing through the

<Problems to be solved by the invention> In order to balance the current flowing through the two horizontal deflection coils, the inductance of the controlled coils 12 and 13 connected in series with each horizontal deflection coil must be uniform. It has to be balanced. In the case of the conventional dynamic convergence correction device described above, the distance between the cores of the pair of drum-shaped cores 14a, 14b and 15a, 15b, in which the pair of controlled coils 12, 13 are dividedly wound, is constant. Therefore, the mutual inductance and magnetic resistance between each pair of cores are not constant, and the inductances of both controlled coils 12 and 13 cannot be balanced.

On the other hand, if the flanges of each pair of cores are brought into contact with each other and the gap between each pair of cores is reduced to 0, it is likely that the mutual inductance and magnetic resistance will be constant. The spacing between each pair of cores is not constant depending on the degree of closeness of the coils and the finish of the contact surfaces, and therefore, as mentioned above, the inductance of the pair of controlled coils 12 and 13 cannot be balanced. It was hot.

<Means for solving the problem> In the present invention, a spacer of a constant thickness is inserted between a pair of cores arranged in parallel, each of which has a pair of controlled coils wound therein, and each rib of both cores is inserted into this spacer. The present invention provides a dynamic convergence correction device in which the peripheral edges of the cores are brought into contact with each other, and the distance between the two cores is kept constant to balance the inductance of a pair of controlled coils.

<Examples> Examples of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a partially sectioned schematic plan view showing the structure of an embodiment of a dynamic convergence correction device according to the present invention. In the present invention, the cores for the pair of controlled coils 12 and 13 are four drum-shaped cores 14a, 14b and 15a, 1.
Two "king" shaped cores 23, 24 instead of 5b
(Of course, the ribs of the two drum-shaped cores may be joined to form a "king"-shaped core), and a spacer 25 of a constant thickness is inserted between the "king"-shaped cores 23 and 24. The circumferential edges of the respective flanges of both cores 23 and 24 are arranged parallel to each other so as to face this spacer 25, and one of the controlled coils 12 is connected to the winding on the left side of the two "King" shaped cores 23 and 24 in the figure. The other controlled coil 13 is dividedly wound into the winding part on the right side of the two "king" shaped cores 23 and 24 in the figure. On the other hand, the control coil 11 is wound around the outer sides of the pair of controlled coils 12 and 13 via a substantially elliptical cylindrical bobbin 26.
In addition, the "King"-shaped core 2 has substantially disk-shaped magnets 27 and 28 magnetized in the thickness direction and arranged in parallel.
It is attached to the outer surface of the outer collar portion of Nos. 3 and 24.

A pair of "king" shaped cores 23 and 24 are connected to the spacer 2
Examples of means for holding the spacer 25 in contact with the spacer 5 include a method of bonding with an adhesive, a method of pressing the spacer 25 in a direction that pinches the pair of cores 23 and 24 using, for example, a phosphor bronze spring, but the present invention is not limited to these methods. It's not a thing.

<Operation> In this type of dynamic convergence correction device, since the divided windings of each controlled coil 12 and 13 are wound in opposite directions on one core 23 and the other core 24, When the distances between the controlled coils 12 and 13 are different, the mutual inductance of the one with the wider distance decreases, and the inductance seen from both ends becomes smaller. Therefore, variations occur in the inductances of both controlled coils.

According to the present invention, a spacer 25 having a constant thickness is inserted between a pair of cores, and the peripheral surfaces of the collar portions of both cores are brought into contact with this spacer 25.
5 is compressed and held by both cores, the distance between the pair of cores is constant at any point along the core axis direction, and the mutual inductance and magnetic resistance between the cores are constant. Become. Therefore, the inductances of both controlled coils 12 and 13 are balanced, and the occurrence of misconvergence can be suppressed.

As mentioned above, if there is no spacer 25, the distance between the cores is theoretically 0, but depending on variations in the shape of the cores, the degree of adhesion, and the finish of the contact surface, there may be a gap on either side. If there is one, the other gap is 0, so the variation in inductance between the pair of controlled coils becomes quite large. On the other hand, if the spacer 25 is inserted, even if there is a difference in the spacing between the cores, the effect will be considerably smaller compared to the case without the spacer, and therefore the variation in the inductance of both coils will be reduced. This makes it possible to suppress the occurrence of misconvergence. For example, if the spacing between one core is 0 and the spacing between the other cores is 0.1 mm, the spacing ratio is 0 mm without a spacer:
0.1mm = 1:∝, whereas when inserting a 0.3mm spacer, the ratio becomes 0.3mm:0.4mm = 1:1.33, which shows how great the effect of inserting the spacer is. Note that if the thickness of the spacer becomes considerably large, it is thought that the effect becomes considerably weaker because a horizontal magnetic field loop cannot be formed. Experimentally, about 0.1 to 0.5 mm is appropriate, but it is not limited to this. In addition, the pair of cores 23 and 24 are connected to the control coil 1.
Alternatively, the spacer 25 may be compressed and held by one bobbin 26 .

<Effects of the Invention> As described above, in the present invention, since the spacer is simply inserted between a pair of cores, there is no manufacturing problem and the cost is not increased.
Furthermore, since the inductances of both controlled coils can be balanced at the stage of pre-processing the device, efficiency is high. Furthermore, even if there is a difference in the spacing between a pair of cores, most of it can be absorbed by inserting a spacer, so variations in inductance between both controlled coils can be absorbed, and misconvergence can be suppressed, among other advantages. There is.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway schematic plan view showing an embodiment of a dynamic convergence correction device according to the present invention, Fig. 2 is a schematic plan view showing an example of a conventional dynamic convergence correction device, and Fig. 3 is a deflection yoke. FIG. 3 is a circuit connection diagram of the device. 11... Control coil, 12, 13... Controlled coil, 23, 24... Core, 25... Spacer,
27, 28...Magnet.

Claims (1)

[Scope of utility model registration request] A pair of almost “king”-shaped cores are arranged in parallel,
Each of the pair of controlled coils is dividedly wound around the pair of cores, the control coil is wound so as to surround the outside of the pair of controlled coils, and a thickness is formed on the outer surface of the outer flange of the pair of cores. In a dynamic convergence correction device equipped with a magnet magnetized in the direction, a spacer of a constant thickness is inserted between the pair of cores, and the spacer is sandwiched between the peripheral surfaces of the respective ribs of the pair of cores. A dynamic convergence correction device that maintains a constant distance between a pair of cores.