JPS603484Y2 - Cathode for cold cathode discharge tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cold cathode discharge lamp, in particular to a cathode of a flash discharge lamp, which has an external starting electrode in addition to an anode and a cathode.

This type of discharge tube has an anode and a cathode at both ends of a glass tube formed into a tubular shape of hard glass or fused silica, etc., and has a starting electrode on the tube wall. By applying a high voltage to the starting electrode, the anode and the cathode are A flash of light is produced by causing a discharge between the cathodes.

Conventional cathodes use a tungsten rod as an electrode lead-in wire that is attached to the end of the tube, and a getter material is attached to the rod by various methods.

An example of a cathode to which this conventional getter material is attached is shown in FIGS. 1 and 2.

In Figure 1, a nickel metal strip is bent into a U shape, both ends of which are fixed to the tip of a tungsten rod 2, and a small piece of getter material 3 is inserted into the space formed by the nickel metal 1 and the tungsten rod 2. It is held in place by pushing it in.

Since this structure is simple, it is suitable for a low-power discharge tube, but as the power increases, the nickel metal 1 melts and the getter material 2 scatters significantly, making it unusable.

The limit is about 3QWsec. FIG. 2 shows a device for high power use, in which a getter material 3 is attached to the side surface of a tungsten rod 2 using a band-shaped nickel metal 1.

Since the tip of the tungsten rod 2 is exposed, ion bombardment occurs at the tip of the tungsten rod 3, and it can withstand large electric power.

However, in any case, since the getter material is simply held by the band-shaped nickel metal, the getter material is likely to fall off, and there is also an accident in which the welded part of the nickel metal comes off due to temperature rise due to ion bombardment.

Further, the work of holding the getter material 3 with the nickel metal 1 and attaching it to the tungsten rod 2 is also complicated.

In particular, when the discharge tube is enlarged and a plurality of getter materials 3 must be attached, it takes a lot of time to manufacture the cathode, which is disadvantageous in terms of economic efficiency.

The present invention was devised to eliminate the above-mentioned drawbacks, and aims to provide a cathode that can withstand high-power discharge, is free from accidents such as the getter material falling off during discharge, and has a structure that is easy to assemble. It is something.

The present invention, which is distantly related to the above object, attaches a getter material to one surface of a support plate formed in the shape of a metal band, bends it into a U-shape with the surface on which the getter material is attached inside, and places an electrode in the center of the support plate. It is constructed by penetrating it.

As the support plate, it is preferable to use a material such as nickel or molybdenum that is easy to process, has a high melting point, and is less prone to sputtering due to electric discharge.

A single plate-like material may be used, but a material having fine mesh may also be used.

The number of getter materials attached to the support plate is not limited to one,
It is possible to attach multiple pieces as needed.

As the electrode rod, it is preferable to use a tungsten rod as in the past.

To explain the illustrated embodiment, numeral 11 is a support plate made of a molybdenum plate formed into a band shape, and two getter materials 13 and 13 are attached to the surface thereof.

As the getter material 13, titanium is used, which is securely fixed to the support plate 11 and has excellent gas adsorption properties at both high and low temperatures.

Other materials such as tantalum, zirconium, thorium, and alloys thereof can also be used.

Furthermore, if welding is performed in an inert gas, it is also possible to use a flash getter.

A small hole 14 is provided in the center of the support plate 11, and as shown in FIG.・
The support plate 11 is made to protrude by about 5 to 2 rran and penetrate through the hole, and is used to fix the support plate 11 to the electrode rod 12 by spot welding.

It is desirable to perform spot welding at a position farthest from the tip of the electrode rod 12.

Due to this configuration, the manufacturing method is extremely simple, as it is only necessary to attach the getter material 13.13 to the support plate 11 in advance, pass the electrode rod 12 through it, and weld the support plate 11 to the electrode rod 12. becomes.

Even if the number of getter materials 13 is increased, there is no problem because the getter materials 13 are welded to a flat plate.

Furthermore, since the ion bombardment occurs at the tip of the electrode rod 12, it can be used satisfactorily even for high-power applications.

There is also an ion bombardment at the U-shaped tip of the support plate 11, but since there is no need to use that part as a welding point, the support plate 1
1 comes off from the electrode rod 12.

In other words, it is possible to eliminate any accidents in which the getter material 13 falls off.

[Brief explanation of drawings]

Figures 1 and 2 are related to the structure of a conventional cathode.
The figure is a perspective view of an embodiment of the present invention, and FIG. 4 is a plan view of an example of the support plate of the present invention. 11: Support plate, 12: Electrode rod, 13 Nigeta wood, 14:
Small hole.

Claims (1)

[Scope of utility model registration request] It consists of a support plate formed in a band shape, a getter material attached to one surface of the support plate, and an electrode rod as an electrode lead-in wire, and the support plate is attached to the electrode rod with the surface on which the getter material is attached inside. A cathode for cold cathode discharge tubes that is installed by penetrating the U-shaped central part.