JPH0887969A - Color cathode ray tube - Google Patents

Abstract

PURPOSE: To finely adjust the radiation direction of each electron beam at high precision by coiling one conductive wire on successively neighboring cores to compose a plurality of magnetic poles and setting the starting position and the finishing position of the coiled wire for each core corresponding to the respective cores. CONSTITUTION: A convergence coil 1 is a ring type and a neck part of a color cathode ray tube is set in the circular middle part 2 of the coil. A core part 3 of the coil 1 is composed of a circular core base part 3A concentric with the space 2 and respective cores 3B unitedly formed with the base part 3A and extended toward the center of the space part 2. Except a pair of cores 3B on the opposite to each other among these eight cores 3B, a conductive wire 4 is coiled on the rest of the cores 3B to make each core compose an electromagnet. The coiled state of the wire on each core 3B is different and the coiling starting position and the finishing position of the conductive wire in respective cores 3B are determined for respective cores 3B independently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and more particularly to improvement of a convergence coil thereof.

[0002]

2. Description of the Related Art A color cathode ray tube is an electron beam for R (red), an electron beam for G (green), from its electron gun structure.
And B (blue) electron beams are irradiated from predetermined positions, and the respective beams pass through the same hole of the shadow mask and are formed adjacent to the back portion of the shadow mask, that is, the inner wall of the display surface. The fluorescent films are impacted so that the respective fluorescent films emit red, green, and blue light.

And, in such a color blank tube,
A deflection coil for deflecting each electron beam in the horizontal and vertical directions with respect to the display surface is provided on the outer periphery thereof, and a convergence coil that can be adjusted so that each electron beam can pass through the same hole of the shadow mask. Is provided.

As this convergence coil, for example, one called an E type or a ring type is known, and in any of them, a plurality of coils are formed by winding one core to successively adjacent cores. It is configured with magnetic poles.

Here, the number of turns of the winding applied to each core is generally small because it is restricted by the shape of the convergence coil or the electric power used.

The convergence coil is described in detail, for example, in Japanese Utility Model Publication No. 57-45748 or Japanese Patent Publication No. 51-71723.

[0007]

However, in the color CRT constructed as described above, in the convergence coil, the positions of the winding start and the winding end of each core are taken into consideration only for the convenience of routing the conductive wire. It was the one that was set uniformly.

For example, a conductor wire wound along the juxtaposed direction of each core is first wound in the first core in one direction (perpendicular to the juxtaposed direction of the cores) of the core. After that, it was pulled out from the one direction, and the second and third cores were also wound in the same manner.

Therefore, by winding the conductor wire in this way, the desired number of turns corresponding to each core is obtained (the number of turns in this case is an accurate number of turns in consideration of the winding start and winding end by the core). However, the error of the magnetic field generated by this is so large that it cannot be ignored because the number of turns of the conductive wire in each core is relatively small.

As a result, it has been pointed out that fine adjustment of the irradiation direction of each electron beam using such a convergence coil has a certain limit and cannot be adjusted with desired accuracy.

Therefore, the present invention has been made under such circumstances, and an object of the present invention is to provide a color cathode ray tube capable of performing extremely fine adjustment of the irradiation direction of each electron beam. To do.

[0012]

In order to achieve such an object, the present invention is basically for finely adjusting the irradiation direction of an electron beam, and the conductors are sequentially adjacent to each other by one conducting wire. In a color CRT equipped with a convergence coil that forms a plurality of magnetic poles by winding a core, the winding start and end positions of the winding in each core are set according to each core. To do.

[0013]

In the color CRT constructed as described above, the number of turns of the conductor wire of each core in the convergence coil becomes accurate according to the core, and therefore the magnetic field generated from this convergence coil shows a desired distribution. Will occur.

Therefore, each electron beam irradiated through such a magnetic field can travel in a predetermined irradiation direction.

Therefore, fine adjustment of the irradiation direction of each electron beam can be performed extremely accurately.

[0016]

2 is a plan view showing an embodiment of a convergence coil applied to a color cathode ray tube according to the present invention.

The convergence coil 1 shown in FIG.
This is a so-called ring type, and the neck portion of a color cathode ray tube (not shown) is positioned in the circular space portion 2 formed in the center thereof.

That is, the neck portion is arranged so that its central axis coincides with the axis passing through the center of the space portion 2 from the back side to the front side in the drawing.

The core portion 3 of the convergence coil 1 has a circular core base portion 3 which is concentric with the center of the space 2.
A, and each core 3B provided integrally with the core base 3A and extending toward the center of the space.

Here, for example, eight cores 3B are provided in a radial pattern at an equal angle to the center of the space 2.

A conductor wire 4 is wound around the remaining cores 3B of the cores 3B except a pair of cores 3B facing each other, and the conductors 4 are respectively wound in the space portion 2 (that is, in the neck portion of the color CRT). An electromagnet that forms the distribution of the magnetic field is configured.

FIG. 3 is an explanatory view showing that two types of such convergence coils are prepared and one of them is selected according to the deflection of the electron beam.

In the figure, (a) is generally called a 6H coil and is used when it is desired to horizontally displace the remaining B and R electron beams with respect to the central G electron beam. It has become a thing. Further, (b) in the figure is generally called a 6V coil, and is used when it is desired to vertically displace the remaining B and R electron beams with respect to the central G electron beam. Has become.

Although FIG. 3 shows separate convergence coils according to their respective uses, it is also known that one convergence coil has these various functions.

Then, for example, in the convergence coil of FIG. 3 (a), the core is
In the case of pole 1, pole 2, pole 3, pole 4, pole 5, and pole 6,
The degree of winding of the core conductor wire at each of these poles is shown in FIG.
As shown in.

As is clear from the figure, the winding state of the conductor wire in each core is different, and the winding start and end positions of the conductor wire in each core are determined according to each core. .

1 (b) and 1 (c), which is shown as another embodiment, in order to obtain a desired number of windings in each core, the start and end of winding of the conductor wire in each core are The position is different.

The characteristics of the winding degree of the conductive wire in this embodiment will be clarified by comparing with the conventional winding degree shown in FIG. In the conventional case, not only the winding start of the conducting wire but also the winding end is set to one side (upward in the drawing).

Here, the case where the windings of the poles 1 to 6 obtained from the magnetic field characteristics of the convergence coil have the values shown in the design values of FIG. 6 will be described as an example.

When the windings of poles 1 to 6 are expanded and shown, conventionally, the winding method shown in FIG. 4 based on an integer number of turns is used. If you get the number of turns close to the design value with this winding
This is the number of times A1 and A2 in FIG. The design value of the number of windings of the pole 4 and the pole 6 is 8.66, but in reality, either 8.25 or 9.25 is selected. Also for pole 5, the design value is selected 11.25 times as opposed to 12.25 times.

On the other hand, as in the embodiment, by adopting the winding method shown in FIGS. 1A to 1C in which one of the winding start and the winding end is changed, B in FIG. , C, D, it is possible to obtain the number of windings closer to the design value. FIG. 7 shows the result of comparing the difference between the design value and the actual winding in%. In the conventional method, as shown by A1 and A2 in FIG. 7, the difference in the number of windings from the design value of each pole (maximum-minimum difference of each pole) is 6 to 11%. On the other hand, the difference width can be reduced by the methods B, C, and D as in the present embodiment, and the difference width by the method D is 1%.

In the convergence coil thus constructed, considering the vector of the magnetic field (FIG. 5B) corresponding to the pole of the core (FIG. 5A), the resultant force is the vector a, Vector b and vector c, of which vector b and vector c have an angle of 45 ° with respect to the reference line, and their combined force (vector d)
Can take a scalar value in the opposite direction to the vector a.

From the above, according to the color cathode-ray tube according to the present embodiment, the number of turns of the conductor wire of each core in the convergence coil is accurate according to the core, so that the magnetic field generated from this convergence coil is It will occur with the desired distribution.

Therefore, each electron beam irradiated through such a magnetic field can travel in a predetermined irradiation direction.

From this fact, fine adjustment of the irradiation direction of each electron beam can be performed extremely accurately.

In the above-mentioned embodiment, the ring type convergence coil has been described, but the present invention is not limited to this, and it can be applied to a so-called E type convergence coil as shown in FIG. 8, for example. Needless to say.

Further, in the present embodiment, the number of turns of the number of turns is shown in increments of 0.25 for convenience of explanation, but it goes without saying that the number of turns is not limited to this.

Further, in the description of the magnetic field vector shown in FIG. 5, a simple case is shown as an example. In practice, the magnetic path, the induction of the horizontal and vertical deflection magnetic fields, and the geomagnetic field are shown. It goes without saying that the specification of the number of turns is determined in consideration of influences and the like.

[0039]

As is apparent from the above description,
According to the color cathode ray tube of the present invention, fine adjustment of the irradiation direction of each electron beam can be performed extremely accurately.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a color cathode ray tube according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a convergence coil used in a color CRT according to the present invention.

FIG. 3 is an explanatory view showing how to use a convergence coil used in the color CRT according to the present invention.

FIG. 4 is an explanatory diagram showing an example of a conventional color CRT.

FIG. 5 is an explanatory view showing the effect of the convergence coil used in the color CRT according to the present invention.

FIG. 6 is an explanatory diagram showing an effect of the present invention in comparison with a conventional example.

FIG. 7 is an explanatory diagram showing the effect of the present invention in comparison with a conventional example.

FIG. 8 is an explanatory view showing another embodiment of the convergence coil used in the color CRT according to the present invention.

[Explanation of symbols]

 1 ... Convergence coil 3 ... Core part 4 ... Conductor

Claims (1)

[Claims] 1. A color cathode-ray tube for finely adjusting the irradiation direction of each electron beam, comprising: a convergence coil having a plurality of magnetic poles formed by winding adjacent cores sequentially with a single conductive wire. The color cathode ray tube characterized in that the positions of the winding start and the winding end of each core are set according to each core.