JPH04123749A - Circular magnet for crt display apparatus - Google Patents

Abstract

PURPOSE:To make the precision of magnetic joining uniform by making a step structure wherein magnetic parts in the inner circumference covering the neck region side of a television picture tube are extruded more than non- magnetic parts. CONSTITUTION:A circular magnet body 1 has a step structure in the inner circumference forming a fixing hole 2 wherein extruded parts 1a-1h for magnetic joining and non-magnetic parts 1i-1p are formed reciprocally and an extruded piece 1x for adjustment is formed in a part of the outer circumference of the circular magnet body 1. At the time of fixing magnetic yokes 10 magnetically to the circular magnet body l, each of extruded pieces 10a-10h of the magnetic yokes 10 are so put as to face to each of the parts 1a-1h for magnetic joining. With this structure. the magnetic fluxes at the time of magnetic fixing of the circular magnet body are converged into the parts for magnetic joining which correspond to the optional number of the poles, and consequently even if the magnetic resistance of the circular magnet body is not uniform, the precision of each of the parts for magnetic joining is improved.

Description

Detailed Description of the Invention [Objective of the Invention (Industrial Application Field) The present invention relates to an annular magnet body for a CRT (cathode ray tube) display device, and more particularly, to a color or monochrome CRT display device. Convergence magnet ring in the device.

The present invention relates to an annular magnet used as a centering magnet ring and a pink John distortion correction magnet ring.

(Prior Art) Generally, in a CRT display device, as shown in FIG. 5, an electron gun 3 is installed in a neck 21 area of a picture tube 20 serving as a CRT main body, and an electron gun 3 is installed in an outer peripheral area of the neck 21. A deflection yoke 4 for deflecting the electron beam emitted from the electron gun 3; a pink John distortion correction magnet ring 5 located in front of the deflection yoke 4 (on the phosphor screen 21a side); It has a configuration in which a convergence magnet ring 6 and a centering magnet ring 7 located on the rear side (electron gun 3 side) of the deflection yoke 4 are attached.

By the way, the pink John distortion correction magnet ring 5. Magnet rings such as the convergence magnet ring 6 and the centering magnet ring 7 (hereinafter referred to as "annular magnet body 8")
Conventionally, as shown in FIG. 6, the neck 2 is formed into an annular shape with a step-free circular hole 9 having an inner diameter that can be attached to the outer periphery of the neck 2, made of a synthetic resin material containing magnetic powder, for example. It has a configuration in which a protruding piece 8x for rotation adjustment is provided protrudingly from a part of the holder.

When used as a magnetic ring for compensating N and S magnetic poles of the annular magnet body 8,
As shown in FIG. 6, this is carried out by a magnetizing yoke 10 having eight protrusions 10a to 10h arranged radially, each of which has four N and four S magnetic poles alternately magnetized. The N and S magnetic poles are arranged alternately and spaced apart from each other at regular intervals to form magnetized portions 8a to 8h having regular intervals, with a total of 8 poles.

(Problems to be Solved by the Invention) However, in the case of the conventional annular magnet body 8 described above, when magnetizing the annular magnet body 8, the inner peripheral side of the annular magnet body 8 is circular and there is no stepped portion. In addition, since the magnetic resistance is not uniform throughout, each protruding piece 10a, 10c of the magnetizing yoke 10.

From 10e and 10g, the magnetized portion 8a8c of the annular magnet body 8,
The flow of magnetic flux toward 8e, 8g is caused by the nonuniform magnetic resistance of the annular magnet body 8, and the magnetic flux flows toward each magnetized portion 8a, 8c, 8e,
There is a problem in that it acts non-uniformly on 8g, causing variations in the accuracy of these S pole magnetizations.

Similarly, during magnetization, each magnetized portion 8b, 8d.

Projections 10b, 10d, 10f from 8f, 8h.

The flow of magnetic flux toward 10h also becomes non-uniform due to the non-uniform magnetic resistance of the annular magnet body 8, and each magnetized portion 8b, 8d
, 8f, and 8h, variations occur in the N-pole magnetization accuracy.

Therefore, the present invention can achieve uniform magnetization accuracy by improving the shape of the magnetized portion, and as a result,
C that can contribute to correcting the position of the electron beam appropriately
The object of the present invention is to provide an annular magnet for an RT display device.

[Structure of the Invention (Means for Solving the Problems)] The present invention provides an annular magnet body that is attached to a neck region of a picture tube of a CRT display device and that corrects the position of an electron beam from an electron gun. It has a stepped structure in which magnetized portions corresponding to an arbitrary number of poles on the inner peripheral side occupying the neck region side of the magnet protrude from non-magnetized portions.

(Function) According to the above-mentioned annular magnet, the step structure in which the magnetized portion protrudes more than the non-magnetized portion is provided on the inner peripheral side that occupies the neck side of the picture tube. The magnetic flux during magnetization is narrowed down to the magnetized portion corresponding to the arbitrary number of poles, and as a result, even if the magnetic resistance of the annular magnet body is uneven, the magnetization accuracy of each magnetized portion can be improved. .

(Example) Examples of the present invention will be described in detail below.

The annular magnet body 1 shown in FIG. 1 is formed into a circular annular shape with a predetermined thickness from a synthetic resin material filled with magnetic powder, and has a protruding magnetized portion 1a on the inner circumferential side facing a substantially circular mounting hole 2. ~1h
It has a step structure having alternating portions and non-magnetized portions 11 to 1p. Moreover, a protruding piece 1x for adjustment is provided on a part of the outer periphery of the annular magnet body 1.

For such an annular magnet l, the magnetizing yoke 1 described above
When magnetizing with 0, as shown in FIG.
h is arranged so as to face each of the magnetized portions 1a to 1h.

As a result, each protruding piece 10a, which is a north pole, and the IOC.

10e, the magnetic flux from Log is in the non-magnetized portion 1i.

Magnetized parts 1a facing each other without spreading to lh, 1m, and io
, lc, 4e, and Ig in a narrowed state,
Even if the annular magnet body 1 has non-uniform magnetic resistance, each magnetized portion 1a, lc, le, Ig is uniformly magnetized and acts as an S pole.

Further, protrusions 10b, 10d, and 10f face each other from the magnetized portions 1b, ld, If, and lh, respectively.

10h is also narrowed down even if there is non-uniform magnetic resistance in the annular magnet body 1, and at this time, the non-magnetized portions 1j, 11. There is no wraparound of the magnetic flux from in and ip, and as a result, each of the magnetized portions lb, ld, if, and lh are uniformly magnetized and act as N poles.

The annular magnet body 1 magnetized in this manner is shown in FIG.

Incidentally, the step structure between the magnetized portion 1a and the non-magnetized portion 11 (the same applies to other portions) may also be formed into a continuous structure with a smooth curve as shown in FIG.

According to the annular magnet body 1 of the present embodiment described in detail above, the magnetized portions 1a to 1h and the non-magnetized portions 11 to 1p are connected to each other with a step difference, thereby reducing the non-uniformity of magnetic resistance. Even if there is, it is possible to uniformly magnetize each magnetized portion 1a to 1h and use it, thereby demonstrating appropriate operation for pink John distortion correction, convergence adjustment, and centering adjustment. It becomes possible to do so.

The present invention is not limited to the embodiments described above,
Various modifications are possible within the scope of the gist.

For example, in the above-mentioned embodiment, the annular magnet 1 having an 8-pole configuration has been described, but other magnets include a 2-pole structure and a 4-pole structure.

It is also possible to implement a magnetic pole configuration with an arbitrary number of poles such as 6 poles or 12 poles.

[Effects of the Invention] According to the present invention described in detail above, due to the above-described configuration, the magnetization accuracy of each magnetized portion becomes nearly uniform even when there is non-uniformity of magnetic resistance. Accordingly, it is possible to provide an annular magnet body with high magnetization accuracy that can contribute to correcting the position of an electron beam appropriately during use.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the annular magnet according to the present invention, Fig. 2 is a plan view of the above magnetized state, Fig. 3 is a plan view of the same after magnetization, and Fig. 4 5 is a partially enlarged plan view showing a modification of the stepped structure of this embodiment, FIG. 5 is a schematic side view of a CRT display device, and FIG. 6 is a plan view of a conventional annular magnet body. 1... Annular magnet body, 1a to 1h... Magnetized part, 1
1 to 1p...non-magnetized portion, 20... picture tube, 21
···neck. Figure r

Claims (1)

[Scope of Claims] In an annular magnet body that is attached to the neck region of a picture tube of a CRT display device and that corrects the position of an electron beam from an electron gun, magnetization is provided on the inner peripheral side that occupies the neck region side of the picture tube. 1. An annular magnet for a CRT display device, characterized by having a stepped structure in which a portion protrudes more than a non-magnetized portion.