JPH071721Y2 - Convergence coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a convergence coil, and more particularly to a structure for supplying a magnetic field to the inside of a cathode ray tube.

[Prior Art] Conventionally, a convergence coil has been used to correct a screen shift of a cathode ray tube (CRT). For example,
Three monochromatic CRTs of each primary color are arranged in parallel, and the images of each primary color are projected on the screen through the lenses that are arranged so as to face the respective fluorescent surfaces, and the colors of the colors related to the combination of these primary color images are projected. In a projection device that obtains a projection screen, a deviation such as distortion due to a projection angle from a monochromatic CRT to the screen occurs on the projection screen. That is, in order to correct the deviation of these screens,
A convergence coil is used, and the direction of projection of the electron beam onto the fluorescent point is adjusted by the coil.

This convergence coil is composed of, for example, a core made of a magnetic material such as ferrite, and a cylindrical bobbin fitted to the core and having a convergence winding wound around the outer periphery thereof. Are oriented around the CRT such that they face the interior of the CRT and, for example, adjacent to the deflection coil. That is, when a current is supplied to the convergence winding and a magnetic field is generated in the core, the CR of the core is
A magnetic field is supplied to the inside of the CRT from the end face facing the inside of the T. In this way, the magnetic field supplied to the inside of the CRT partially corrects the projection direction of the electron beam, which is given the necessary deflection by the deflection coil, to the fluorescent point of the CRT. At this time, compared to when the current is not supplied to the convergence winding,
The beam is projected on different fluorescent points of the CRT. Therefore,
According to this convergence coil, it is possible to adjust the projection direction of the electron beam to the fluorescent point and correct the screen deviation by supplying the current to the convergence winding.

On the other hand, in recent years, in order to obtain a high resolution screen, a high frequency has been used as a horizontal scanning frequency. That is, in order to increase the number of scanning lines and obtain a high-resolution screen, it is necessary to set the frequency related to horizontal scanning, that is, the horizontal scanning frequency high.

CRT with such a high horizontal scan frequency
However, there is a problem in that the amount of heat generated by the deflection coil due to the current of the frequency increases. That is, when the horizontal scanning frequency is set high, the amount of heat generated by the eddy current generated in the deflection coil increases. This problem is the same when a current is passed through the convergence coil, and as a means for solving this problem, there is, for example, the one disclosed in Japanese Utility Model Laid-Open No. 63-108154. In this means, a piece of magnetic material is closely fixed to one end face of the core of the convergence coil facing the inside of the CRT, and the piece of magnetic material has a length larger than that of the core.

With the convergence coil having such a magnetic material piece, it is possible to prevent an increase in heat generation even when the horizontal scanning frequency is set high. That is, the magnetic field generated in the core by the current of the convergence winding is expanded according to the extension of the magnetic material piece with respect to the core. Therefore, the sensitivity of the convergence coil is improved, and the screen shift correction by the convergence coil can be more effectively performed. Therefore, even when the horizontal scanning frequency is set high, the necessary beam deflection can be performed with a small amount of current by increasing the amount of adjustment of the beam projection direction by the convergence coil, and problems such as heat generation can be prevented. You can

[Problems to be Solved by the Invention] However, in the conventional convergence coil having such a configuration, the manufacturing process involved in closely fixing the magnetic material piece to the core and fixing the bobbin to the core and the bobbin structure are complicated. However, there was a problem related to manufacturing cost such as complication. That is, when the magnetic material piece is closely fixed to the core with an adhesive, for example, a manufacturing process such as adhering the magnetic material piece to the core with an adhesive is required, which leads to an increase in manufacturing cost. Was there. Further, when the magnetic material piece and the core are integrally formed and the magnetic material piece is tightly fixed to the core, the bobbin cannot be attached to the core by fitting the tubular bobbin. A bobbin having a complicated structure is required, such as joining two bridge-shaped bobbin pieces with the core sandwiched therebetween to mount the bobbin on the core, which has led to an increase in manufacturing cost including component cost.

The present invention has been made to solve the above problems, and an object thereof is to provide an inexpensive convergence coil with improved sensitivity due to the expansion of the magnetic path for supplying a magnetic field into the CRT. To do.

[Means for Solving the Problems] In order to achieve the object, the present invention provides a leg portion inserted between a core and a bobbin, and a vertical direction from one end of the core facing the inside of the cathode ray tube to the outside of the core. And a magnetic path expansion piece made of a magnetic material having a magnetic permeability larger than that of the core, the magnetic path expansion piece being generated when a magnetic field is generated in the core by the current of the convergence winding. A magnetic field is supplied to the inside of the cathode ray tube via the.

[Operation] In the convergence coil of the present invention, the magnetic field generated in the core by the current of the convergence winding is supplied to the inside of the cathode ray tube through the magnetic path expansion piece. At this time, since the magnetic path for supplying the magnetic field to the inside of the cathode ray tube is expanded by the magnetic path expansion piece, the sensitivity of the convergence coil for adjusting the beam projection direction is improved.

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

FIG. 1 shows the configuration of a convergence coil according to the first embodiment of the present invention.

For example, a core 12 is provided on the periphery of the CRT so as to be adjacent to the deflection coil, and a convergence yoke 10 made of a magnetic material such as ferrite faces the inside of the CRT. A bobbin 14 having a convergence winding (not shown) wound around the outer periphery thereof is fitted on the core 12.
That is, a magnetic field is generated in the core 12 by the convergence winding current.

The magnetic path expansion pieces 16 and 18 according to the features of the present invention are made of a magnetic material having a magnetic permeability higher than that of the core.
And overhang portions 16b and 18b. Further, the magnetic path expansion pieces 16 and 18 are closely fixed to the core 12 by inserting the leg portions 16a and 18a between the upper and lower side surfaces of the core 12 and the upper and lower inner side surfaces of the bobbin 14, respectively, and the protruding portions. The parts 16b and 18b are provided so as to project vertically from one end of the core 12 facing the inside of the CRT. That is, the magnetic field generated in the core 12 by the current in the convergence winding is
End facing the inside of the CRT and the extension 1 of the magnetic path expansion pieces 16 and 18
It is supplied to the inside of the CRT from 6b and 18b.

With the convergence coil having such a configuration, it is possible to improve the sensitivity for adjusting the beam projection direction. That is, the magnetic path related to the magnetic field supplied from the core 12 to the inside of the CRT is expanded by the magnetic path expansion pieces 16 and 18 according to the features of the present invention, and the magnetic field supplied through the expanded magnetic path causes CR
The projection direction of the electron beam inside T is adjusted. In this way, the ratio of the adjustment amount of the beam projection direction to the current of the convergence winding, that is, the sensitivity of the convergence coil is improved.

Further, the convergence coil according to this embodiment can be manufactured at a lower cost than the conventional convergence coil having the magnetic material piece. That is, the magnetic path expansion pieces 16 and 18 according to the features of the present invention can be easily adhered and fixed to the core 12 by inserting the magnetic path expansion pieces 16 and 18 between the core 12 and the bobbin 14. Without complication,
Fixation can be done. Therefore, an increase in manufacturing cost can be prevented.

As described above, according to the convergence coil of this embodiment, the magnetic flux related to the magnetic field supply to the inside of the CRT is expanded, and the sensitivity related to the magnetic field supply can be improved. Furthermore, this convergence coil can be manufactured at low cost.

FIG. 2 shows the configuration of the convergence coil according to the second embodiment of the present invention. In this figure, the core 12 is omitted.

In this embodiment, the overhanging portion 16 of the magnetic path expansion pieces 16 and 18 is
b and 18b are provided so as to project in the left-right direction as compared with the first embodiment.

According to the convergence coil of this embodiment, the first
It is possible to obtain the same effect as that of the embodiment. Further, in this embodiment, the overhanging portion 16b of the magnetic path expansion pieces 16 and 18 is
Since the surface areas of 18 and 18b are larger than those in the first embodiment, C
It is possible to further improve the sensitivity to the convergence coil for supplying the magnetic field into the RT.

FIG. 3 shows the configuration of a convergence coil according to the third embodiment of the present invention.

In this embodiment, the leg portions 16a of the magnetic path expansion pieces 16 and 18 are
And 18a are inserted between the left and right side surfaces of the core 12 and the left and right inner side surfaces of the bobbin 14, and the overhanging portions 16b and 18b are formed in the core 12.
It is provided so as to project from the one end facing the inside of the CRT to the left and right.

According to the convergence coil of this embodiment, the first
It is possible to obtain the same effect as that of the embodiment.

FIG. 4 shows the configuration of a convergence coil according to the fourth embodiment of the present invention. In this figure, the core 12 is omitted.

In this embodiment, the overhanging portion 16 of the magnetic path expansion pieces 16 and 18 is
b and 18b are provided so as to project in the vertical direction as compared with the third embodiment.

According to the convergence coil of this embodiment, the third
It is possible to obtain the same effect as that of the embodiment. Further, in this embodiment, the overhanging portion 16b of the magnetic path expansion pieces 16 and 18 is
Since the surface area of 18 and 18b is larger than that of the third embodiment, C
The magnetic field can be more effectively supplied to the inside of the RT, and the sensitivity of the convergence coil related to the magnetic field can be further improved.

[Effects of the Invention] As described above, according to the present invention, the magnetic path related to the magnetic field supply to the inside of the CRT can be expanded by the magnetic path expansion piece to improve the sensitivity of the convergence coil related to the magnetic field supply. . Furthermore, this convergence coil can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram of a convergence coil according to a first embodiment of the present invention, FIG. 2 is a block diagram of a convergence coil according to a second embodiment of the present invention, and FIG. FIG. 4 is a configuration diagram of the convergence coil according to the third embodiment, and FIG. 4 is a configuration diagram of the convergence coil according to the fourth embodiment of the present invention. 12 …… Core 14 …… Bobbin 16, 18 …… Magnetic path expansion piece 16a, 18a …… Magnetic path expansion piece leg 16b, 18b …… Magnetic path expansion piece overhang

Claims (1)

[Scope of utility model registration request] 1. A tubular body having a core made of a magnetic material facing the inside of the cathode ray tube so as to supply a magnetic field to the inside of the cathode ray tube; In the convergence coil having a bobbin, a leg portion inserted between the core and the bobbin, and an overhang extending vertically from one end of the core facing the inside of the cathode ray tube to an outside direction of the core. And a magnetic path expansion piece made of a magnetic material having a magnetic permeability higher than that of the core, and when a magnetic field is generated in the core by the current of the convergence winding, a cathode wire is formed through the magnetic path expansion piece. A convergence coil that supplies a magnetic field inside the tube.