JP3161029B2 - Internal magnetic shield and cathode ray tube for cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal magnetic shield for a cathode ray tube and a cathode ray tube, and more particularly, to an internal magnetic shield for a cathode ray tube which does not cause inconvenience such as "cracking" at the time of loading, and an internal magnetic shield for the cathode ray tube. The present invention relates to a cathode ray tube.

[0002]

2. Description of the Related Art Geomagnetism exists inside a cathode ray tube (CRT) used for a color television (TV). As means for preventing the displacement of the electron beam affected by the terrestrial magnetism, an inner magnetic shield (Inner Magnetic Shield:
IMS) is known. This IMS is used by being welded to the frame of the color selection mechanism mask.

FIG. 3 is a perspective view for explaining the structure of a cathode ray tube (CRT). As shown in FIG. 3, the CRT is mainly composed of a funnel 1 shown in FIG. 3 (a) and an internal magnetic shield (IMS: inner magnetic shield) shown in FIG. 3 (b).
2, a color selection mechanism mask (AG: aperture grille) 3 shown in FIG. 3C and a panel 4 shown in FIG. 3D, and the IMS 2 and the AG 3 are connected to the funnel 1 as shown in FIG. A set is assembled between the panels 4. The IMS 2 is fixed to the frame of the AG 3 by welding at a predetermined position as described above.

In FIG. 3A, reference numeral 5 denotes a neck tube, in which an electron gun 5a is arranged and an electron beam is emitted.

The above-described IMS 2 may be stacked (stacked) in several stages during the manufacturing process. In this case, since each IMS naturally has the same shape, it overlaps exactly with the upper and lower parts, so that so-called "cracking" is caused and it is hard to separate. Therefore, a structure has been devised to prevent the "smearing" of the IMS.

FIG. 4 shows a conventional I which prevents the above-mentioned cracking.
It is a perspective view showing MS (internal magnetic shield) structure.

The IMS 2 is composed of an A component 7 and a B component 8, as shown in FIG. 4, corresponding to the long side and the short side of the panel of the CRT. It has a side wall 9 and a short side wall 10 to protect the electron beam from geomagnetism.

In the conventional IMS 2 shown in FIG. 4, a part of the side wall is folded back at the lower end of each of the side walls of the A part 7 and the B part 8 so that the upper and lower shielded products do not cause "cracking" when stacked. Tongue-shaped support pieces 12 formed in this manner (in the figure, two on each side wall, a total of eight). FIG.
It is the schematic which piled up the IMS2 provided with the said support piece 12, and each IMS2 floats up and down slightly by the support piece 12, and can separate the upper and lower shield goods easily.

As a second conventional method for preventing the above-mentioned IMS 2 from cracking, as shown in FIG. 6, a flat portion following each side wall of the IMS 2 is provided at three locations (upper and lower sides) on the upper and lower stacked products. Two places on one of the two A parts,
There is known a structure in which one (one) projection 13 (projection) is formed on the other one of the A parts, and the two projections and one projection forming position are alternately changed up and down.

[0010]

In the above-described first structure for preventing crazing, the holes 14 are formed in the side walls of the component A on the long side of the IMS and the component B on the short side, respectively. The geomagnetic drift characteristics were worse than in the case where no support member was provided, and the support piece 12 had a thickness of the A component 7 or the B component 8, that is, only one sheet. .

In the structure in which a projection (projection) 13 is provided on a plane portion of the IMS 2, the A component 7 or the B
Since the shape of the component 8 becomes two types, that is, the A component 7 having two convex portions and the A component 7 having one convex portion, the cost for the mold increases, and the IMS increases.
Assembly management man-hours increased.

Accordingly, the present invention provides an internal magnetic shield for a cathode ray tube and an internal magnetic shield for a cathode ray tube which reduce man-hours by improving the geomagnetic drift characteristics and increasing the strength to enable mass loading. It is an object of the present invention to provide a cathode ray tube having the same.

[0013]

According to the present invention, there is provided an internal magnetic shield for a cathode ray tube, wherein at least two or more steel plates are partially overlapped and connected in a frame shape. Characterized in that a projection is provided on the outer steel plate. The internal magnetic shield for a cathode ray tube according to the present invention further includes, in an internal magnetic shield for a cathode ray tube formed by joining two sets of opposed steel plates partially by welding and connecting them in a frame shape, projecting against the outer steel plate of the overlapping portion. The present invention is characterized in that a unit is provided.

The cathode ray tube according to the present invention includes an internal magnetic shield for a cathode ray tube in which at least two or more steel plates are partially overlapped and connected in a frame shape, and a projection is provided on an outer steel plate of the overlapped portion. It is characterized by having. The cathode ray tube according to the present invention further includes an inner magnetic shield for a cathode ray tube in which two sets of opposed steel plates are partially overlapped by welding and connected in a frame shape, and a projection is provided on an outer steel plate of the overlapped portion. It is characterized by having.

In the present invention, it is preferable that the protrusion is formed by drawing or folding.

[0016]

According to the present invention, the convex portion 20 is formed on the outer (upper) steel plate of the superposed portion 19 of the steel plate forming the magnetic shield by drawing or the like. Therefore, the steel plate also exists below (inside) the convex portion, and when the IMS 2 is stacked (stacked), the upper and lower two steel plates form the upper I
Since the MS is supported, the supporting strength can be increased, and the upper and lower IMSs can be easily separated.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an internal magnetic shield (IM) of the present invention.
It is a perspective view which shows one Example of S).

In FIG. 1, the same elements as those of the prior art are denoted by the same reference numerals.

In this embodiment, as shown in FIG. 1, a B component (outside steel plate) of a superposed portion 19 of a steel component A 7 having a long side wall 9 and a steel component B having a short side wall 10 is provided. )
(Projection) 2 by drawing at 4 places
0 is provided symmetrically. Two sets each of the A component 7 and the B component 8 are welded to each other in a frame shape by resistance welding or the like.

FIG. 2 is a view showing a state in which the IMSs 2 each having the convex portion 20 formed on the overlapping portion 19 as shown in FIG. 1 are stacked (stacked). Due to the double steel plate thickness, it is firmly and stably supported. The thickness of the IMS 2 is about 0.3 mm,
0 may be about 0.5 to 1 mm.

The stacking of the IMS is performed by combining the IMS 2 and FIG.
Color selection mechanism mask 3 (aperture grill: A
G) and an IM with a convex portion 20 in this embodiment when supplied to a welding attachment device (IMS welding machine).
In S2, the work was performed efficiently and efficiently without cracking between the upper and lower parts of the IMS.

In the above embodiment, the convex portion 20 of the overlapping portion 19 of the A component 7 and the B component 8 is formed by drawing, but a structure in which a part of the upper component of the overlapping portion is cut off and folded back may be used.

[0024]

As described above, according to the internal magnetic shield for the cathode ray tube and the cathode ray tube of the present invention, the loading of the internal magnetic shield (IMS) can be supported at the position of the double part without the occurrence of sticking. In addition, a large amount can be supplied by increasing the strength. Therefore, man-hours at the time of welding the IMS and the color selection mechanism mask can be reduced.

Further, since a hole (opening) is not formed as in the case of the conventional tongue-shaped support piece, the geomagnetic drift characteristics are improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an internal magnetic shield (IMS) of the present invention.

FIG. 2 is a diagram of the IMS shown in FIG.

FIG. 3 is a perspective view showing a configuration of a cathode ray tube.

FIG. 4 is a perspective view showing an example of a conventional IMS.

FIG. 5 is a schematic view of the IMS shown in FIG.

FIG. 6 is a schematic plan view showing another example of the conventional IMS.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Funnel 2 Internal magnetic shield 3 Color selection mechanism mask (AG) 4 Panel 5 Neck tube 5a Electron gun 7 A component 8 B component 9 Long side wall 10 Short side wall 12 Tongue-shaped support piece 13, 20 Projection (projection) ) 14 holes 19 overlapping part

Claims (6)

(57) [Claims] 1. An internal magnetic shield for a cathode ray tube formed by connecting at least two or more steel plates partially and connected in a frame shape, wherein a projection is provided on an outer steel plate of the overlapping portion. Internal magnetic shield for pipes. 2. An internal magnetic shield for a cathode ray tube, wherein two sets of opposed steel plates are partially overlapped by welding and connected in a frame shape, wherein a projection is provided on an outer steel plate of the overlapped portion. Internal magnetic shield for cathode ray tubes. 3. The internal magnetic shield for a cathode ray tube according to claim 1, wherein the projection is formed by drawing or folding. 4. An internal magnetic shield for a cathode ray tube, wherein at least two or more steel plates are partially overlapped and connected in a frame shape, and a projection is provided on an outer steel plate of the overlapped portion. Cathode ray tube. 5. An internal magnetic shield for a cathode ray tube comprising two sets of opposed steel plates that are partially overlapped by welding and connected in a frame shape, and a projection is provided on an outer steel plate of the overlapped portion. And a cathode ray tube. 6. The cathode ray tube according to claim 4, wherein the projection is formed by drawing or folding.