JPS61190842A - Metal vapor discharge lamp - Google Patents

Abstract

PURPOSE:To suppress the rise in start voltage at the initial stage of lighting, by providing a plurality of getters in an outer tube, and placing at least one of the getters in a position where the temperature becomes not higher than about 350 deg.C at the time of lighting, and by raising the temperature of the getter to activate it before the lighting. CONSTITUTION:A luminous tube 1, which is fitted with electrodes 2a, 2b and in which a rare gas, mercury and an iodide of scandium or the like are sealed, is provided in an outer tube 3 in which nitrogen gas is sealed, so that a metal vapor discharge lamp is constructed. A getter 16 made of a zirconium-aluminum alloy or the like is welded on a support frame 15. An annular getter 17 made of the same substance as the getter 16 is secured to the frame 15, in a position where the temperature becomes not higher than about 350 deg.C at the time of lighting. Before the lighting, the getter 17 is heated over 800 deg.C by a high-frequency induction heater or the like so as to be activated to adsorb hydrogen in the outer tube 3 to reduce the partial pressure of hydrogen. The rise in start voltage can thus be suppressed to improve the lighting property of the lamp.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to metal vapor discharge lamps such as metal halide lamps, and in particular to improving the starting characteristics thereof.

[Conventional technology]

Conventionally, this type of rung, for example, a 1000W metal halide ring made by Mitsubishi Electric, has a structure similar to the second factor. In the figure, reference numeral 1 denotes an arc tube with electrode structures 2a and 2b at both ends, and an appropriate amount of rare gas, mercury, scandium, and sodium iodide is sealed in a translucent quartz tube.
Both ends of the arc tube 10 are held by a holding plate 14, and the holding plate 1
'4 is fixedly welded to a support frame 15, and a leaf spring 12 is attached to one side of the support frame 15 and held by the outer tube 3.

A stem lead 11 is fixedly welded to the other side of the support frame 15 and extends by being connected to one side of the base 4 provided at the end of the outer tube 3, and is connected to the lead 7b via the support plate 15 and the lead 13. , is connected to the electrode 8b via the metal foil 6b. Also, the stem lead 10 extending from the other side of the base 4 is connected to the electrode 8a via the thin lead 9, the lead 7a and the metal foil 6a. Zirconium aluminum alloy The r ivy 16 consisting of is arranged at a part that has a predetermined operating temperature and is fixedly welded to the support frame 15. The outer tube 3 is filled with nitrogen gas at a predetermined pressure. This is a heat-retaining membrane provided at the lower end of the tube 1.

In the metal halide lamp having the above configuration, when it is connected to a power source via a safety device (not shown) and started, first the base 4 - stem lead 10 - reden lead 9 - lead 7a -
Metal foil 6a - Electrode 8a - Electrode 8b - Metal foil 6b - Lead 7b - Rigan lead 13 - Support frame 15 - Stem lead 1
Current flows through 1-base 4-ballast, and the arc tube 1 gradually becomes hotter, the discharge stabilizes, and normal light emission occurs. When this lamp is turned on with the cap 4 facing upward, the nitrogen gas inside the outer tube 3 causes convection due to the heat generated by the arc tube 1, and the getter 16 reaches a predetermined operating temperature. Impure gas (particularly hydrogen gas) in the outer tube 3 is gradually absorbed by the getter 16. When the rung is turned on for a long time, the hydrogen partial pressure inside the outer tube 3 decreases. When the hydrogen partial pressure inside the outer tube 3 becomes lower than the hydrogen partial pressure inside the arc tube 1, the hydrogen inside the arc tube 1 gradually diffuses through the wall of the arc tube 1 and flows out into the outer tube 3. come. Hydrogen flowing into the outer tube 3 is adsorbed by the getter 16, and the hydrogen partial pressure inside the arc tube 1 and the outer tube 3 is kept low, making it possible to suppress an increase in starting voltage during the life.

[Problems to be Solved by the Invention] However, the adsorption effect of the conventional getter 16 described above is more pronounced than when it is lit for a long time (in units of hundreds of hours), and the lighting time of the rung is short. (in units of several tens of hours), the effect is small and the starting voltage increases.Also, if you try to operate in a short time, the adsorption ability of the getter 16 will decrease during its life, and the starting voltage will increase during its life. had the disadvantage that it would increase and lose its effectiveness.

This invention was made in order to solve the above-mentioned problems, and its purpose is to reduce the increase in starting voltage during its life from the initial stage of lighting, and to obtain a metal vapor discharge lamp with stable specific characteristics. .

[Elaborate means to solve problems]

The metal vapor discharge lamp according to the present invention includes a plurality of getters in the outer bulb, activates at least one of the getters, and places the activated getter in a position where the temperature is less than 350°C during lighting. , which attempts to suppress the rise in starting voltage at the initial stage of lighting.

[Effect]

When a getter made of a zirconium aluminum alloy is activated by raising the temperature to 800° C. or higher using a high-frequency induction heating device or the like before lighting the lamp, the getter rapidly performs an adsorption action and lowers the hydrogen partial pressure inside the outer tube. This activated getter is placed at a temperature below 350° C. so as not to re-release the gas adsorbed by the heat of the lamp during lighting. Further, the getter, which is to operate stably for a long time, is installed in a part where the temperature is between 350° C. and 450° C. during lighting, and is caused to perform an adsorption operation.

〔Example〕

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

Reference numeral 17 is a getter made of zirconium aluminum alloy formed into a ring shape, and the getter 17 is fixedly welded to the support frame 15 near the stem lead 110. The other configurations are the same as before.

In the metal vapor discharge lamp with the above configuration, getter 1 is
7 using a high frequency induction heating device or the like, pso.

Activate by increasing the temperature to ℃ or higher. This activated getter 17 rapidly adsorbs hydrogen within the outer tube 3 and lowers the hydrogen partial pressure within the outer tube 3. After that, it is connected to a power source via a stable wind as in the conventional case.

As a result, when the metal vapor discharge lamp is lit, the hydrogen partial pressure inside the outer bulb 3 is significantly lower than the hydrogen partial pressure inside the arc tube 1.
The tube wall of arc tube 1, which is hot during stable lighting, is
The hydrogen inside passes through by diffusion or the like and is adsorbed by the stock getter 17, so that the residual hydrogen inside the arc tube 1 can be reduced in a short time.

It is possible to prevent an increase in starting voltage at the initial stage of lighting.

Here, the above-mentioned scandium and sodium are added to the arc tube 1.
A 100 OW metal halide lung sealed in the lamp was prepared, and the relationship between lighting time, starting time, and pressure, that is, starting voltage characteristics, was measured. The results are shown in the following table and FIG. 3 in comparison with the conventional method. In FIG. 3, "A" indicates the present embodiment, and "1" indicates the conventional example.

As is clear from the diagram and FIG. 3, the metal halide lamp of this example can significantly improve the starting voltage rise at the initial stage of lighting, and can also lower the starting voltage during its life.

In the above embodiment, the getter 17 is formed into a ring shape, but the same effect can be obtained with other shapes. Further, although the mounting position of the getter 17 is shown near the cap 4, the same effect can be obtained at any position within the outer bulb 3 as long as the temperature is less than 350° C. during lighting.

〔Effect of the invention〕

As described above, in the present invention, a plurality of getters are provided inside the outer bulb and at least one of them is activated, and this getter, which operates in a short time, sufficiently exhibits the gas adsorption effect even in the initial stage of lighting. This makes it possible to suppress the increase in starting voltage. Further, the starting voltage during the life is also suppressed by the getter that operates for a long time and the getter. The reason why the activated getter is placed in a position where the temperature becomes less than about 380 DEG C. during lighting is to prevent the adsorbed gas from being released again.

[Brief explanation of the drawing]

Fig. 1 is a front view of a metal vapor discharge lamp according to the present invention, Fig. 2 is a front view of a conventional metal vapor discharge lamp, and Fig. 3 is a starting voltage characteristic diagram of a metal vapor discharge lamp according to the present invention and a conventional metal vapor discharge lamp. be. 1... Arc tube, 3... Outer tube, 16.17... Getter. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) An arc tube and a plurality of getters made of zirconium aluminum alloy are provided in the outer bulb, and at least one getter is activated and placed in a position within the outer bulb where the temperature is less than about 350°C when the light is turned on. A metal vapor discharge lamp characterized by: