JPS5885264A - Electric-discharge lamp - Google Patents

Abstract

PURPOSE:To enhance both the cooling effect of an anode and a cathode as well as the emissional attenuation caused due to sputtering, and increase the life of an electric-discharge lamp by interposing metal networks between the inner wall of the case and the anode and the cathode so as to make them in soft contact with each other. CONSTITUTION:The side surfaces of an anode 3 and a cathode 2 are provided with fibrous or net-like metals 6 and 7 made of tungsten, Monel, nickel or the like. The metals 6 and 7 are composed of networks of, for example, around 100-500 wires per inch, and are fixed to the anode 4 and the cathode 2 each at several points by spot welding or the like after being loosely wound around the side surfaces of the anode 3 and the cathode 2. As a result, a quartz tubular case 1 becomes in soft contact with the anode 3 and the cathode 2. Consequently, the cooling effect of the anode 3 and the cathode 2 can be enhanced, and the life of an electric-discharge lamp can be extended.

Description

[Detailed description of the invention] The present invention relates to improvements in discharge lamps.

Discharge lamps are widely used these days for excitation of laser tubes, etc.
A container made of a transparent quartz tube or the like is provided with a cathode and an anode made of tungsten or the like at both ends, and the container is filled with an inert gas such as xenon or crimpton. The operating principle of this type of discharge lamp is to apply a voltage to the cathode and anode to generate gas discharge within the container and emit light. At this time, ionized gas ions and electrons are It collides with the object and heats it to extremely high temperatures. As a result, both electrodes sputter and form a film on the inner surface of the quartz tube container, reducing the amount of light emitted outside the tube, or the electrodes are heated too much and the contact between the electrodes and the quartz tube container is reduced. There were problems such as thermal distortion occurring in the sealing part of the quartz tube and cracking of the quartz tube container.

Therefore, such a discharge lamp is usually housed in a transparent container made of glass or acrylic, cooled by a cooling wooden surface poured into the container, and operated from the front. Furthermore, in conventional discharge lamps, in order to make the water cooling effect more effective near the electrodes, the diameter of the quartz tube near the electrodes is made particularly thin, and the space between the quartz tubes and the electrodes is shaped to be extremely small. structure has been adopted.

However, a discharge lamp having such a structure has the drawback that while the cooling effect is only slightly improved, the shaping operation of the quartz tube vessel is difficult and extremely inefficient.

The present invention has been made with the aim of eliminating such drawbacks, and provides easily and inexpensively a discharge lamp that further improves the cooling effect and reduces the occurrence of electrode spatter and cracks in the quartz tube container. It is something.

Instead of narrowing the distance between the container 1 and the electrode by shaping the quartz tube container, the present invention interposes a metal mesh between the shell container and the electrode to bring them into soft contact.
It is characterized by significantly improved cooling effect. Next, the present invention will be explained with reference to the drawings. Figure 1 is a cross-sectional view showing the structure of a conventional discharge lamp. 1 is a container with a transparent quartz tube;
A cathode 2 and an anode 3 made of tungsten or the like are hermetically sealed with the container 1 at both ends thereof. Both electrodes (cathode 2
and the recess of the container 1 provided near the anode 3) and the anode 3).
is a shaped part to increase the cooling effect, and is connected to the inner wall of the container 1,
It is shaped so that the distance between it and both electrodes is narrowed to about 0.2 to 0.5-. The purpose of this is to not extend the water cooling effect during operation to both electrodes as efficiently as possible through the container 1 and the gas filled therein, such as xenon or krypton. Such shaped portions 4 and 5 are usually formed by a so-called glass shaping operation during a step in which the interior of the container is evacuated after the quartz tube container 1 having a uniform diameter and both electrodes 2 and 3 are hermetically sealed. ing. However, such shaping work is an extremely difficult work that requires skill, and if the gap between the inner wall of the container and the electrode is too narrow and there is partial contact, the container may crack at the contact area during operation, resulting in poor yield. It was also bad and inefficient. In addition, the method of providing a desired recess in the container 1 in advance is extremely expensive considering the precision of a general quartz tube, and the distance between the inner wall of the recess and the electrode is 0.000 mm in the process of hermetically sealing the container and the electrode. It was even more difficult and practically impossible to work without eccentricity so that the angle was about 2 to 0.5.

The present invention eliminates such drawbacks and provides a discharge lamp that is inexpensive and easy to manufacture, and FIG. 2 is a sectional view showing an embodiment thereof. In this example, cathode 2 and anode 3
Fiber-like or mesh-like metals 6 and 7 made of, for example, tungsten, monel, nickel, or the like are provided on the side surfaces. For example, the optimum number of metal wires and wires 7 per inch is about 100 to 500 wires per inch, and it is preferable to wrap them lightly around the side of the electrode and then fix them by spot welding at several points because they have good elasticity. Such metal metjuro and 7
By providing a quartz tube container 1 and both electrodes 2 and 3,
In addition to the gas filled in the container 1, the water cooling effect from the container 1 is transmitted to the electrodes through the metal mesh, which has good thermal conductivity. Therefore, it is no longer necessary to shape the container 1; The manufacturing process is extremely simple. In addition, since the metal rods 7 have high elasticity and are in soft contact with the inner wall of the container 1, no excessive force is applied and the container 1 does not crack during operation.

FIG. 3 shows another embodiment of the present invention, and is a diagram in which only the vicinity of the anode 3 is enlarged. In this embodiment, a recess is provided in the side surface of the anode 3, and the metal mesh shear is housed in the recess. By adopting such a structure, it becomes easy to hold the metal mech S7, and at the same time, the total thickness of a part of the mech can be increased, which increases elasticity and becomes more effective.

The discharge lamp of the present invention is extremely easy to manufacture as described above, has an improved electrode cooling effect compared to conventional discharge lamps, and has improved light emission attenuation caused by electrode sputtering. The effects are very large, such as extending one's life.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the structure of a conventional discharge lamp, FIG. 2 is a cross-sectional view showing an embodiment of the present invention, and FIG. 3 is an enlarged view of the vicinity of electrodes showing another embodiment of the present invention. 1...Transparent quartz tube, 2...Cathode, 3...
...Anode, 6.7...Mesh metal.

Claims (1)

[Claims] In a discharge lamp in which a cathode and an anode are hermetically sealed at both ends of a transparent glass tube container, and an inert gas is filled inside the container, there is a fiber or mesh between the cathode and anode and the inner wall of the container. A discharge lamp characterized by having a shaped metal interposed therein.