JPH0317401Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to joining a spacer of a fluorescent display tube and a metal part connected to the spacer.

[Conventional technology]

In conventional fluorescent display tubes, as shown in FIG. 2, a filament support 1 is fixed to a spacer 2 at several locations by resistance welding.

[Problem that the invention attempts to solve]

Compared to the thickness of the spacer 2, the thickness of the filament support 1 is about 1/4, and the difference in heat capacity between the two is large. For this reason, in the resistance welding method, in which a large current is instantaneously applied and local heating is performed by Joule loss, only the filament support 1 is heated. Therefore, it has poor weldability and is difficult to weld. Alternatively, if a slight force is applied to the filament support 1 or the grid 5 during post-welding work, a problem occurs in which the filament 1 comes off from the spacer 2. For this reason, as shown in FIG. 3, the entire surface of the contact portion of the spacer 2 with the filament support 1 is reduced in thickness by about 50% by etching or the like. As a result, the difference in heat capacity at the welded portion of the spacer 2 and the filament support 1 is reduced, and weldability is improved. However, in the case of the etching method, if the etching area is large, it is difficult to control the amount of etching, the plate thickness varies from place to place, and weldability at thick parts is not improved. Furthermore, as the plate thickness becomes thinner, mechanical strength is significantly impaired. In this case filament 3
The tension applied to hold the spacer 2 without sagging may cause deformation of the spacer 2. Furthermore, there is a high possibility that deformation will occur when the spacer 2 is handled during the work process. Also, when connecting the grid 5 and the spacer 2, the grid 5
Since the plate thickness of spacer 2 is about 1/4 thinner than that of spacer 2, the above-mentioned problem occurs.

[Means for solving problems]

The purpose of this invention is to improve the weldability of the filament support and grid to the spacer without impairing the mechanical strength of the spacer. A limited number of layers are thinned using techniques such as etching.

〔Example〕

An embodiment according to the present invention will be specifically described using FIG. 1.

Four circular welds 4 each having a diameter of 1 mm are provided on the joint surface of the spacer 2 with the filament support 1. The plate thickness of the welded portion 4 is approximately 1/2 the original plate thickness of the spacer 2. The filament support 1 and the spacer 2 are welded at the weld 4 using a resistance welding method.

In the embodiment shown in FIG. 1, welding is performed at all locations of the weld 4, that is, at four locations.

[Effect of idea]

As explained above, in the present invention, the spacer is provided with a thin portion only at the welded portion between the spacer and the filament support, so the mechanical strength of the spacer is not impaired due to the thinning. Therefore, the possibility of spacer deformation caused by applying tension to the filament and spacer deformation due to careless handling during the work process is
becomes extremely small. With a diameter of approximately 1 mm, variations in wall thickness that occur during etching are small, and the wall thickness of the welded portion is also approximately constant, resulting in stable weldability. Furthermore, by limiting the welded portion to a welded portion with a diameter of about 1 mm, it is possible to reduce the variation in welding positions among operators.

In the example shown in Fig. 1, the diameter of the welded part is 1 mm.
However, it varies depending on the shape of the welding electrode, etc., and is not limited to 1 mm. Furthermore, the plate thickness of the welded portion needs to be changed depending on the plate thickness of the spacer, and is not limited to half the conventional plate thickness of the spacer as in the embodiment. Furthermore, although the embodiments of the present invention have been described using the joints between the spacer and the filament support, it goes without saying that the present invention can also be applied to other welds, such as the joints between the grid 5 and the spacer.

[Brief explanation of drawings]

FIG. 1a is a perspective view of the present invention, and FIG. 1b is a perspective view of the present invention.
2 is a conventional perspective view, FIG. 3 is a perspective view with the entire contact area between the filament support 1 and spacer 2 thinned out, and FIG. BB line sectional view of. 1...Filament support, 2...Spacer,
3...Filament, 4...Welding part, 5...Grid.

Claims (1)

[Scope of utility model registration request] In a light display tube comprising an anode substrate coated with a phosphor in a specific pattern, a filament that emits electrons, and a grid that diffuses and controls the electrons, the filament support is resistance welded to the spacer at multiple locations. . A fluorescent display tube, characterized in that the thickness of the spacer is made thinner than the surrounding area only at the resistance welded portion between the spacer and the filament support.