JPH03210749A - Single-sealed metal-vapour discharge lamp - Google Patents

Abstract

PURPOSE:To reduce the irradiation of ultraviolet rays to a getter by providing an emission tube having pressure sealed parts that seal a pair of electrodes, and a getter that absorbs an impurity gas, and by arranging them on positions which satisfy specified conditions. CONSTITUTION:The outer diameter of the sphere of an emission tube 2 in the direction of a pressure sealed part as D1, the thickness of the pressure sealed part as D2, and the angle theta between a flat surface including discharge parts 7 of a pair of electrodes 5 as well as a getter 10, and a flat surface in parallel to the surface of the pressure sealed part, including the boundary between a sphere part 3 and the pressure sealed part 4, are determined. In order to cut ultraviolet rays irradiated to the getter at the pressure sealed part of the emission tube, an expression I is to be satisfied. For the condition that does not cause the extinction of sodium, an expression II is to be satisfied, where a minimum interval between the sphere 3 of the emission tube and the getter 10 is L1, while the length of the pressure sealed part 4 is H1. The extinction of luminous metal can thus be avoided without enlarging an outer tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a single-sealed small metal vapor discharge lamp that is applied to a small metal halide lamp 1 and the like.

(Prior Art) In recent years, small metal soot discharge lamps used for indoor and outdoor lighting, etc. have been produced, and recently a pair of electrodes has been sealed only at one end of the arc tube. A so-called single-sealed structure is being considered.

Also, this type of lamp is disclosed in Japanese Patent Application Laid-Open No. 59-54167, for example.
As shown in the publication, sodium halide or the like is selected as the luminescent metal sealed in the arc tube, and impurities such as zirconium alloy are selected to maintain a high vacuum inside the outer tube that airtightly accommodates the arc tube. A getter may be installed to absorb the .

<Problems to be Solved by the Invention> In the case of the above-mentioned DIL single-sided carved metal vapor discharge lamp, the size of the outer bulb is made as small as possible, so the distance between the getter and the arc tube is minimized. It is difficult to space them apart.

Therefore, the arc tube is easily irradiated with the emitted ultraviolet rays, and due to the photoelectron effect, light-emitting metals with small primitive radius such as sodium sealed in the arc tube disappear outside the arc tube. There was a problem.

The present invention aims to provide a single-sealed metal vapor discharge lamp that can reduce the irradiation of the ultraviolet getter without increasing the size of the outer bulb, thereby eliminating the disappearance of the luminescent metal. It is.

[Structure of the Invention, 1 (Means for Solving the Problems) In order to solve the above problems, the single-sealed metal vapor discharge lamp of the present invention includes a spherical part filled with a starting rare gas, a luminescent metal, and mercury. , having a discharge site that maintains discharge within the spherical part; an arc tube having a pair of electrodes, and a crushing sealing part formed integrally with the spherical part and sealing the pair of electrodes; and this arc tube. This single-sealed metal vapor discharge lamp is equipped with an outer bulb that airtightly accommodates the gas, and a dowel getter that is disposed inside the outer bulb and adsorbs impure gas. The diameter is ■)1, and the thickness of the crushed sealing part is D2. - The angle between the plane containing the discharge site of the village electrode and the gate and the plane parallel to the surface of the pressure sealing section containing the boundary between the spherical part and the crushing sealing part is θ, and the spherical If the short distance between the part and the getter is L1, and the length of the crushed sealing part is T11, then 5 games...
9- is.

t, a n θ ≦ D2. /'DIL1≧11
, 2 cos θ.

(For 'tE) In the present invention, the outer diameter of the bulbous part of the arc tube in the direction of the crushed sealing part is +11, the diameter of the crushing sealing part is D2, and the plane including the discharge part of the counter electrode and the getter.

Parallel to the surface of the pressure sealing lE part including the boundary between the spherical part and the crushed sealing part = l/, the angle between the plane and the surface is ρ, the shortest distance between the spherical part and the geritter is L1, the crushing sealing part When the length of is 81, the getter placement position is t a n θ ≦
D2/”DI L 1 ≧ Ml ”2 cos
θ, it is possible to provide a single-sealed metal vapor discharge lamp that can reduce the irradiation of the getter with ultraviolet rays without increasing the size of the outer bulb, thereby eliminating the loss of 11Y in the luminescent metal.

(Embodiment) An embodiment of the present invention will be described in detail with reference to the drawings.5 As shown in Fig. 1, a single-sealed metal vapor discharge lamp with a lamp power of 150 W according to the present invention, for example, quartz glass, etc. An arc tube 2 made of quartz glass or the like like the outer bulb 1 is hermetically housed in an outer bulb 1 made of a heat-resistant, light-transmitting material.

This arc tube 2 has a substantially elliptical spherical part 3 with an internal volume of about 1.3 cc, and a crushing seal g4 formed integrally with the spherical part 3 at one end of the spherical part 3. 9 Also, the electrodes 1f! are arranged so that a pair of electrodes 5 protruding from one spherical part 3 are spaced apart in the width direction of the crushing sealing part 4 of the arc tube 2. 5
The shaft portions 6 of the electrodes 5 are sealed substantially parallel to the crushing sealing portions 4, and the discharge portion 7 located at the left end of the electrode 5 is oriented with respect to the extending direction of the electrode shaft portion 6 in order to maintain stable discharge. They are configured to be bent and face each other, and have a length of 7+sm in horizontal distance from the electrode shaft part 6 to the opposing direction.

In order to increase the heat capacity, the discharge site 7 of the electrode 5 is provided with a wire diameter of about 0.5 or more, for example.・It contains about 2 parts of aluminum and is wrapped with a coil made of triatevdota.

Electrode l! The part 6 is made of a rhenium-tungsten alloy with a wire diameter of about 0.5, and its ends are connected to crush-sealed metal foil conductors 8 made of g/4 molybdenum or the like, and the metal foil The conductors 8 are each connected to an outer conductor 9.

In addition, a predetermined amount of mercury, sodium chloride 1, thallium, indium, and a starting rare gas are sealed in the spherical part 3, and in the case of this example, 281 (1 /'CC mercury and S n I 2
, Na1. TIT, 10 [, N a B r, ■, iB
r is enclosed.

As shown in Figure 2, the side surface of the arc tube [4] is a vacuum cleaner that adsorbs impurities and maintains a high vacuum inside the outer tube.
A getter 10 made of an alloy such as aluminum-aluminum is supported by the outer conductor 9 and is spaced apart from the plane of the crush sealing part 4.

After manufacturing a large number of discharge lamps as described above, we found that in many of the discharge lamps, in order to increase the distance between the arc tube and the getter, the getter was placed far away from the side surface of the second part of the crushing seal 11. It was confirmed that significant changes occurred in lamp characteristics such as lamp voltage, lamp power, lamp luminous flux, and lamp light color during the lighting life.

The inventors of the present invention conducted extensive research into the cause of this problem, and found that it is caused by the getter being charged by ultraviolet irradiation, attracting the luminescent metal that is the inclusion, and causing the luminescent metal to disappear from the arc tube. 3 This is because in conventional resealable discharge lamps, the two arc tube support members or getters that generate photoelectrons are separated from the arc tube. , a method has been adopted to reduce the adsorption of luminescent metal by charged members such as the getter, but in this type of single-sealed discharge lamp, the getter and luminous tube are affected by the miniaturization of the outer bulb. It was found that a sufficient separation distance could not be maintained between the camera and the camera, and therefore it was essential to have a configuration that would prevent ultraviolet rays from being irradiated to the camera.

Therefore, in this type of single-sealed discharge lamp, rather than adding Mk+ to the distance between the getter and the arc tube, the inventor proposed that the ultraviolet rays emitted to the getter be blocked by the crushed sealing part of the arc tube. When the distance from the flat surface of the crush sealing part to the getter was made small while keeping in mind the technical concept of making it possible to reduce the temperature, the above-mentioned changes in characteristics were significantly reduced.

That is, the outer diameter of the arc tube spherical portion in the direction of the crushing sealing portion is D1.
, the thickness of the crushed sealing part is D1, the surface of the crushing sealing part including the plane including the discharge site of the village electrode and the gebuter, and the boundary N between the spherical part and the crushing sealing part, and the surface of the crushing sealing part including the boundary N: When the angle between the plane and the plane is defined as θ, in order to block the ultraviolet rays emitted to the getter by the crushed sealing part of the arc tube, the geometric relationship is t, a n θ ≦ D2/' It turns out that it is enough to satisfy DI.

However, even when the getter is arranged in the above configuration, if the arc tube and getter are brought too close together, the getter's optimum operating temperature range may be exceeded due to heat radiation from the arc tube. It was confirmed that there is a phenomenon in which the ultraviolet rays reflected by the tube are irradiated onto the getter, which becomes electrically charged and attracts the luminescent metal.5 Therefore, the shortest distance between the spherical part of the arc tube and the getter (Ll
), the length of the crush seal (Hl) and the above-mentioned angle (
We produced 100 discharge lamps with different factors such as θ) and conducted an experiment to see how sodium disappeared after lighting them for 3000 hours.The following results were obtained.

(Left below) From the above experimental results, the conditions that do not cause the disappearance of Natriu 1 are when the shortest distance between the spherical part of the arc tube and the lid is L1, and the length of the crushed sealing part is Hl. , L 1 ≧[1/'2co s θ.

Also, if the getter is provided close to the sealing part of the outer tube,
When sealing the outer tube, the getter may deteriorate due to oxidation.
In addition, since the ambient temperature may be lower than the maximum MIJt operation of the getter during lighting of the discharge lamp, the jt short distance tilt (Ll) between the arc tube spherical part and the getter is determined by the length of the crushed sealing part (Hl). ) is preferably set smaller than .

Furthermore, in cases where the getter is supported by one of the external conductors as in item 2, the potential is the same as that of the external conductor and the metal foil conductor to which the getter is connected, and the other is at a different potential. Because there is some concern that an electrolytic crack at the sealing part or external discharge may be induced between the outer conductor and the metal foil conductor, the distance between the getter and the metal foil conductor, which has a different potential, should be set at least 3111 degrees. It is even more preferable to arrange it in parallel.

In addition, although the above example describes the disappearance of satorium, similar results were obtained for lithium 1, and it has been confirmed that the above-mentioned configuration can prevent its disappearance. 9Also, zirconium-aluminum 14 alloy is used as the gear.
For example, the same effect as in the above embodiment can be expected using materials such as zirconium alone, titanium, barium-based ketters, etc., which have the property of attracting luminescent metals when irradiated with ultraviolet rays.

[Effects of the Invention] According to the present invention described above, a spherical part in which a starting rare gas, a luminescent metal, and mercury are sealed, a pair of electrodes having a discharge part that maintains discharge within this spherical part, and a pair of electrodes integrated with the spherical part. an arc tube, each having a crushing sealing plate which is formed to seal a pair of electrodes;

It is equipped with an outer tube that airtightly accommodates the arc tube, and a getter that is disposed inside the outer tube and adsorbs impurity gas. Thickness is D
2. ~・The angle between the plane containing the discharge site of the counter electrode and the getter and the plane parallel to the surface of the crushed sealing part including the boundary between the sphere part and the crushing sealing part is 05 the shortest distance between the sphere part and the getter. When the distance is L1 and the length of the crushed sealing part is ■1,
Since the getter is placed at the position where t, a n θ ≦ D2/Dt L1 ≧ H12 cos θ, it is possible to
It is possible to provide a single-sealed carved metal vapor teaching lamp that can reduce the irradiation of ultraviolet rays to the getter and thereby eliminate the disappearance of the luminescent metal.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a single-sealed carved metal vapor discharge lamp according to an embodiment of the present invention, and FIG. 2 is a side view of the arc tube shown in FIG. 1. 1... Outer tube 3... Spherical part 5... Electrode 10... Getter 2... ... Arc tube 4 ...... Crushing sealing part 7 ...... Discharging part

Claims (1)

[Scope of Claims] A spherical part in which a starting rare gas, a luminescent metal, and mercury are sealed, a pair of electrodes having a discharge part for maintaining discharge within the spherical part, and a pair of electrodes formed integrally with the spherical part, an arc tube each having a crushing sealing part for sealing an electrode of the arc tube, an outer tube that airtightly accommodates the arc tube, and a getter that is disposed within the outer tube and adsorbs impurity gas; The getter has an outer diameter of the spherical part in the direction of the crushed sealing part D1, a thickness of the crushing sealing part D2, a plane including the discharge part of the pair of electrodes and the getter, the spherical part and the crushing part. The angle between the surface of the crushed sealing part including the boundary with the sealing part and a parallel plane is θ, the shortest distance between the spherical part and the getter is L1, and the length of the crushing sealing part is H
1, a single-sealed metal vapor discharge lamp is disposed at a position where tanθ≦D2/D1 L1≧H1/2cosθ.