JPS603849A - Metal vapor discharge lamp - Google Patents

Abstract

PURPOSE:To obtain a metal vapor discharge lamp with the low starting voltage and excellent light output life performance by providing a translucent film to prevent the reaction between metal halogenide and a quartz tube wall on the inner surface of a luminous tube except one portion. CONSTITUTION:Luminous metal halogenide, e.g., scandium, sodium, is sealed in a luminous tube 1 made of quartz together with a proper quantity of mercury and rare gas. In addition, a translucent film 3 mainly composed of aluminum phosphate, titanium oxide, aluminum oxide, etc. is formed on the inner surface of the luminous tube 1 made of quartz. A notch 4 to pass impure gas is provided at one portion of this translucent film 3. Accordingly, the reaction between the metal halogenide and quartz tube wall is suppressed by the translucent protective film 3 formed on the inner surface of the luminous tube, on the other hand, the impure gas entering during production, etc. permeates and diffuses outside the luminous tube through the notch 4 to be adsorbed by a getter material 7, thereby the impure gas concentration in the luminous tube is reduced, the starting voltage is lowered, and the light output life performance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Uninvented, quartz Xj ("(L61 inside the arc tube) is made of quartz Xj sealed with a metal halide along with mercury and cloth gas to prevent a reaction between the metal halide and the quartz tube wall. This invention relates to improvements in metal vapor discharge lamps coated with metal coatings.

In a /rk flj lamp in which a metal halide is sealed in a quartz arc tube, the metal halide and quartz, which is the material of the arc tube, react with each other during operation, causing the luminescent metal to disappear or to the quartz tube wall. The light output decreases due to the adhesion of reaction products. In addition, silicon (Sl) released into the arc tube by the reaction described above forms a low melting point compound (alloy) with tungsten in the electrode material, causing 'Rt44 deformation and an increase in lamp voltage. .

Therefore, it has been proposed to apply a transparent coating made of metal phosphate or metal arsenate to the inner surface of the quartz arc tube in order to prevent the reaction between the metal halide and the quartz tube wall as described above. I'm here. Such a light-transmitting film is dense and chemically stable, and by adding h-, the reaction between the metal nologide and the quartz tube 1i, τ' can be almost completely prevented. However, when such a transparent coating was applied, Mekokin 4.
Fat air release 'T1i lamp): f, 41! It became clear in 1'11 that the starting characteristics and stroke characteristics deteriorate with 'r I. When we investigated the cause of this, we found that the above-mentioned translucent coating generally does not allow impurity gases such as hydrogen gas to pass through, and impurity gases that are mixed in with the small wire gas and metal halides that remain in the arc tube during manufacturing. It was found that this was caused by the particles remaining in the arc tube as they were.

The present invention has been made to eliminate the above-mentioned drawbacks, and provides a metal vapor discharge lamp which prevents the reaction between metal halides and the quartz tube wall, and which is less affected by impurity gases and has good starting characteristics. This is terrifying.

FIG. 1 shows an example of a metal vapor discharge lamp embodying the present invention, and numeral 1 is a quartz arc tube having electrodes 2a and 2b at both ends. This quartz arc tube 1
A light-emitting metal halide such as scandium or sodium is sealed inside the tube 7 along with an appropriate amount of mercury and a rare gas. Further, on the inner surface of the quartz arc tube 1, phosphorus 1'I (
A translucent coating 3 whose main component is aluminum, titanium oxide, aluminum oxide, etc. is formed. This is a notch 4 for passing a part of the light-transmitting coating 3, for example, the entire inner surface of the arc tube. Heat insulating films 5a and 5b are formed on the outer surface of the quartz arc tube 1 around the electrodes. This quartz arc tube 1 has a pair of supporting conductors 6.
It is supported inside the outer sphere 7 by a and 6b. 8 is a getter material whose main components are aluminum, zirconium, etc.

In order to compare the effects of the present invention with the conventional metal vapor discharge lamp f1;
In addition to [3], there are also discharge lamps ([3] in which no transparent coating P is provided on the inner surface of the arc tube, and discharge lamp G in which a transparent coating is provided on the entire inner surface of the arc tube). As a result, in the discharge lamp (B) without a transparent coating on the inner surface of the arc tube,
As the lighting time progressed, the starting tonnage IE changed as shown in Figure 2 03). The light output of one node is approximately 43. (After 100 hours of lighting, there was a sharp drop in the temperature, and evidence of a reaction between the metal halide and the quartz tube wall was observed.

In addition, a discharge lamp (Q
Then, the starting pressure 1E pressure id (Figure 2) remained at 1, and the light output decreased significantly within a short period of time.

This is because the impure gas that has entered the arc tube is blocked by the transparent coating 3 and does not permeate and diffuse outside the arc tube, so the starting voltage is increased and the oxidation-reduction reaction (water cycle) of tungsten, which is the electrode material, is increased. It is presumed that the tungsten accelerated and moved to the tube wall within a short period of time, causing a decrease in optical output.

While being suppressed by the coating 3, impurity gas mixed during manufacturing is transmitted through the notch 4 of the transparent coating BIA 3 to the outside of the arc tube R+L, and is adsorbed by the getter 7;
IE Ir, J 2nd and 1 wide), the optical output range is also good and A-1, and 10 to 1 each) j, 'l, 'li1. Moon (A),
When the hydrogen gas in the light emission '#f at 8 degrees Celsius was analyzed using an underwater collection method for each lighting time of 0) and 0, the results were as shown in Table 1.

Table 1 (Hydrogen gas concentration in the arc tube (PPm)) According to the present invention, a part of the inner surface of the arc tube is provided with a transparent coating that prevents the reaction between the metal halide and the quartz tube wall. ■The reaction between the metal halide and the quartz tube wall is caused by the impurity inside the arc tube passing through the notch of the transparent coating and the quartz tube wall and being adsorbed by the getter attached to the outer sphere. Gas concentration decreases.

As a result of the above effects, a metal vapor discharge lamp with low charging pressure and good light output range can be obtained. The total area of the transparent coating formed on the inner surface of the luminescent tube varies depending on the size of the gold silk halide and tf4 to be sealed, and must be determined experimentally, but it should be at least approximately the total internal area of the luminescent tube. Requires a size of 3 or more.

As described above, according to the present invention, h is extremely 1 to 11 A,
By this means, the starting time is 1n, the pressure is low, and the light output is jl! l
fI! The present invention has great industrial utility value because it can be used as a metal vapor discharge lamp with good quality.

[Brief Description of the Drawings] Fig. 1 is a partially cutaway side view of a metal vapor discharge lamp embodying the present invention, and Fig. 2 is a starting-up of a gold FJ% vapor discharge lamp according to the present invention and a conventional metal vapor discharge lamp. It is a voltage change curve diagram. Figure 1

Claims (1)

[Claims] In a discharge lamp, a transparent coating is applied to the inner surface of a quartz arc tube in which a metal halide is sealed together with mercury and a rare gas to prevent a reaction between the metal halide and the quartz tube wall. Remove a part of the photosensitive membrane and make it easier for impure gas to pass through from inside the arc tube. 1. All silk fabric with a characteristic? Chi release and light.