JP2000215847A - Metal vapor discharge lamp and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal vapor discharge lamp and a lighting system capable of eliminating and avoiding adhesion of carbon to the outer surface of an arc tube during lighting, and holding the stable whole light flux and a color rendering property. SOLUTION: The metal vapor discharge lamp in this invention has an arc tube 3 in which starting inert gas, light emitting metal, and a pair of discharge electrodes 2a, 2a' are sealed; electricity introduction bodies (lead wires) 2c, 2c' connected to the discharge electrodes 2a, 2a', introduced through an arc tube 3 wall and seals 1b, 1b'; an outer connecting part 4a for connecting to the electricity introduction bodies 2c, 2c', and an envelope tube 4 inside which the arc tube 3 is sealed; and inert gas and oxygen gas are sealed in the envelope tube 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal vapor discharge lamp, and a lighting device using the metal vapor discharge lamp as a light source, and more particularly to a metal vapor discharge lamp and a lighting device in which a reduction in total luminous flux is prevented.

[0002]

2. Description of the Related Art In a quartz arc tube body, for example, a starting inert gas such as xenon, neon or argon, mercury, an excessive amount of luminous metals such as sodium or rare earth halides, A metal vapor discharge lamp provided with an arc tube in which the above-mentioned discharge electrodes are sealed has attracted attention as a highly efficient light source having excellent color rendering properties. That is, this kind of metal vapor discharge lamp is a metal halide lamp,
It is practically used in lighting facilities of various facilities.

FIG. 1 is a cross-sectional view showing a configuration of a main part of a metal halide lamp. In FIG. 1, reference numeral 1 denotes an arc tube main body, and reference numerals 2a and 2b denote a pair of discharge electrodes which are hermetically sealed in the arc tube body 1 so as to face each other. Here, the arc tube main body 1 is airtightly closed / sealed 1b, 1b 'by crushing the open end of a heat-resistant translucent material, for example, a quartz tube (tube) 1a. The discharge electrodes 2a and 2a 'have a configuration in which a coil is wound around an electrode shaft. One end of the electrode shaft is electrically connected to the conductor foils 2b and 2b 'to be connected, and the lead wires 2c and 2c' connected to the conductor foils 2b and 2b '. One end of the electrode shaft, one end of the conductor foils 2b, 2b 'and one end of the lead wires 2c, 2c' are closed and sealed 1b, 1b 'by crushing / sealing the open end, and the lead wire 2 is placed outside the arc tube main body 1.
The configuration is such that c and 2c 'are derived by sealing. The arc tube body 1 is filled with a rare earth halide and the like together with the inert gas for starting. Further, a starting discharge electrode 2a ″ is sealed in the vicinity of one of the discharge electrodes 2a (2a ′) to constitute the arc tube 3.

[0004] Further, 4 is a lead wire 2c of the arc tube 3,
This is a protective envelope having an external connection portion 4a (base) connected to 2c 'and sealing the arc tube 3. Here, the arc tube 3 is supported in the outer tube 4 by a frame 5 resiliently mounted in the outer tube 4 and a support 5a. That is, the luminous tube 3 closing / sealing 1b, 1b 'is supported and mounted on the frame 5 resiliently mounted in the outer tube 4 with the support 5a, while the external connection portion 4a of the outer tube 4 is provided. A wire 6 for electrically connecting the light emitting device to the light emitting device is insulated and supported, and the arc tube 3 is incorporated in the outer tube 4.

In this type of metal vapor discharge lamp, the excess amount of the encapsulated light-emitting metal is so-called minimum when the lamp is lit in consideration of required efficient light emission and maintaining and exhibiting good color rendering properties. It is configured to aggregate and store in the cold part.
In addition, an inert gas of about 300 to 500 torr is sealed in the outer tube 4, and the pressure in the outer tube 4 is set to about 1 atm during lamp operation to prevent implosion when the outer tube 4 is broken.

[0006]

However, the metal vapor discharge lamp having the above structure has the following disadvantageous problems in practical use. That is, when impurities such as carbon are present in the inert gas sealed in the outer tube 4 enclosing the arc tube 3, carbon selectively adheres to the outer surface of the arc tube 3 during lighting. There is a problem that the total luminous flux is reduced.

[0007] As a countermeasure, it has been reported that oxygen in an inert gas is oxidized and removed by enclosing and disposing in an oxygen dispenser (for example, AgO) outer tube 4 and oxygen released from the oxygen dispenser. Yes (1998
, “The 8th International Symposium of the S
cience & Technolgy of Light Sourcos LS-8 ”) However, in this method, it is assumed that oxygen is released from the oxygen dispenser at the operating temperature.
Not enough heating in the exhaust process. That is, assuming that the heating temperature is increased and the air is efficiently exhausted in the exhaust process of the outer tube 4, oxygen is released from the oxygen dispenser in the exhaust process. Therefore, the metal vapor discharge lamp manufactured and assembled is not supplied with sufficient oxygen at the time of lighting, so that the above-described problem of a decrease in the total luminous flux cannot be sufficiently solved. The present invention has been made in view of such circumstances, and eliminates and avoids the adhesion of carbon to the outer surface of an arc tube during lighting, and a metal vapor discharge lamp and a lighting device that hold and exhibit a stable total luminous flux. The purpose is to provide.

[0008]

According to the first aspect of the present invention, there is provided an arc tube in which a starting inert gas, a light emitting metal and a pair of discharge electrodes are sealed; a wall of the arc tube connected to the discharge electrode; A metal vapor discharge lamp comprising: a lead wire that is sealed and led; and an outer tube having an external connection portion connected to the lead wire and sealing an arc tube, wherein the inert tube is inert in the outer tube. This is a metal vapor discharge lamp in which gas and oxygen gas are sealed.

According to a second aspect of the present invention, in the metal vapor discharge lamp according to the first aspect, the inert gas in the envelope is nitrogen gas.

A third aspect of the present invention is the metal vapor discharge lamp according to the first or second aspect, wherein the partial pressure of the oxygen gas in the envelope is 0.1 torr to 4 torr.

The inventions of claims 1 to 3 are based on the following findings. That is, in a metal vapor discharge lamp in which an inert gas is sealed in an envelope, while a small amount of oxygen gas is mixed in the inert gas in a metal vapor discharge lamp in which a metal vapor discharge luminous tube is sealed, the luminous tube during operation is turned on. It was confirmed that the selective adhesion of carbon to the outer surface was easily avoided or reduced, and the reduction of the total luminous flux of the metal vapor discharge lamp was significantly improved.

Here, the amount of oxygen gas in the inert gas is about 0.1 torr to 6 torr, preferably 0.1 torr to about 6 torr.
It is about 4torr. In other words, the amount of oxygen gas in the inert gas is 0.025% by volume to 1.5% by volume, preferably 0.025% by volume.
When the oxygen content is less than 0.1 torr, the effect of improving the total luminous flux is low. When the oxygen content exceeds 6 torr, not only the mount material such as the frame in the envelope is easily oxidized, but also the gating agent is used. Since it is easily oxidized, there is a concern that the life will be shortened.

According to the first to third aspects of the invention, in a metal vapor discharge lamp in which a metal vapor discharge arc tube is sealed in an outer tube, an inert gas and a small amount of oxygen gas are sealed in the outer tube. And In other words, it is assumed that a metal vapor discharge lamp in which an arc tube is sealed in an envelope tube is used, and as long as such a configuration is adopted, generally, all conventionally known metal vapor discharge lamps are targeted. However, the subject is not limited to these.

According to a fourth aspect of the present invention, there is provided the metal vapor discharge lamp according to any one of the first to third aspects, and a lighting fixture equipped with the metal vapor discharge lamp and having a lighting circuit for lighting the metal vapor discharge lamp. And a main body.

In the first to third aspects of the present invention, a gas containing an inert gas as a main component and a small amount of oxygen gas is sealed in the envelope, so that heat radiation can be reduced or good luminous efficiency can be maintained. In addition, the carbon component in the inert gas is easily oxidized and removed at the time of lighting. That is, since the phenomenon that carbon contained as an impurity adheres to the outer surface of the arc tube is entirely prevented or eliminated, the total luminous flux due to the carbon adhesion does not decrease.

In particular, in the invention of claim 2, since the inert gas is nitrogen gas, it is advantageous in terms of cost and the like, and in the invention of claim 3, the carbon component in the inert gas is turned on at the time of lighting. Is more easily and effectively oxidized and removed.

According to the fourth aspect of the present invention, since the light source is a metal vapor discharge lamp that does not cause a reduction in the total luminous flux during lighting, the metal vapor discharge lamp has a high efficiency and a high color rendering property and is stable. Functions as an energy-saving lighting device.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS.

FIG. 1 is a sectional view showing a configuration example of a 400 W input metal halide lamp. In FIG. 1, reference numeral 1 denotes an arc tube main body, and reference numerals 2a and 2b denote a pair of discharge electrodes which are hermetically sealed in the arc tube body 1 so as to face each other. Here, the arc tube main body 1 is airtightly closed / sealed 1b, 1b 'by crushing the open end side of a quartz glass tubular portion (tube) 1a having an inner diameter of about 20 mm and a wall thickness of about 1.8 mm. Also, the discharge electrodes 2a, 2a '
Has a configuration in which a coil is wound around an electrode shaft (for example, a tungsten rod) and the distance between the electrodes is about 40 mm.

One end of the electrode shaft is electrically connected to a conductor foil (for example, molybdenum foil) 2b, 2b 'to be connected and lead wires 2c, 2c' connected to the conductor foil 2b, 2b '. At the same time, one end of the electrode shaft, one end of the conductor foils 2b, 2b 'and one end of the lead wires 2c, 2c' are closed / sealed 1b, 1b 'by crushing / sealing the open end of the cylindrical portion 1a. The lead wires 2c, 2c 'are sealed out of the arc tube body 1. In addition, a rare earth halide (for example, a Sc—Na metal halide) and the like are sealed in the arc tube body 1 together with the inert gas for starting, and one discharge electrode 2a (2a ′). The starting discharge electrode 2a ″ is sealed in the vicinity of the luminous tube 3 to constitute the arc tube 3.

Reference numeral 4 denotes lead wires 2c, 2 of the arc tube 3.
This is a protective glass envelope that has an external connection portion 4a (base) connected to c ′, and seals the arc tube 3. Here, the arc tube 3 is supported and mounted in the outer tube 4 by a frame 5 or the like resiliently mounted in the outer tube 4. That is, while the frame 5 and the support 5a resiliently mounted in the envelope 4 support the arc tube 3 closing / sealing 1b, 1b ', the frame 5 and the support 5a are connected to the external connection portion 4a of the envelope 4. The wiring 6 for electrically connecting between them is insulated and supported, and the arc tube 3 is
Is incorporated.

Further, nitrogen gas 4
A mixed gas system of 00torr and 1torr of oxygen gas is sealed. In other words, in the surrounding pipe 4, the nitrogen gas 400torr
The arc tube 3 is sealed in a mixed gas system of oxygen gas and 1 torr. Next, an example of the characteristics of the metal halide lamp will be described.

As shown in FIG. 2, a general lighting circuit built-in type lighting fixture 7 was prepared for a metal halide lamp. Thereafter, the metal halide lamp 3 was mounted as a light source on the lighting fixture 7 to form a lighting device.
In the drawing, reference numeral 8 denotes a reflecting mirror. The required power is input to this lighting device, and the total luminous flux after lighting for 100 hours is
It was 42000lm.

For comparison, in the configuration of the metal halide lamp described above, the sealed gas in the outer tube 4 was changed to 400 tons of nitrogen gas.
A similar test evaluation was conducted on a 400 W power input metal halide lamp under the same conditions except that only rr was used, and the total luminous flux after lighting for 100 hours was 40,000 lm.

Further, as another example, the same effect as in the case of the metal halide lamp was observed in the case where the arc tube was a so-called mercury lamp, a 400 W power input high-pressure mercury lamp.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, a metal halide lamp of the type and standard other than the 400 W power input type, and a high pressure mercury lamp can obtain the same operation and effect even with a type and standard other than the 400 W power input type.

[0027]

According to the first to third aspects of the present invention, carbon contained as an impurity in the inert gas sealed in the envelope is easily oxidized and removed at the time of lighting. Then, as the adhesion of carbon to the outer surface of the arc tube is completely eliminated, a reduction in the total luminous flux is also avoided, and the above-described metal discharge lamp excellent in practicality exhibiting the original high luminous efficiency and color rendering properties. Will be provided.

According to the fourth aspect of the present invention, since the above-mentioned metal vapor discharge lamp is used as a light source, a stable and energy-saving lighting device with high efficiency, high color rendering and high efficiency is provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration example of a metal vapor discharge lamp.

FIG. 2 is a cross-sectional view showing an example of a configuration of a main part of a lighting device using a metal vapor discharge lamp as a light source.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Arc tube body 1a ... Tubular part (tube) 1b, 1b '... Closure / sealing 2a, 2a' ... Discharge electrode 2a "... Discharge electrode for starting 2b, 2b '... Conductor foil 2c, 2c '... Lead wire 3 ... Arc tube 4 ... Surrounding tube 4a ... External connection part (base) 5 ... Frame 5a ... Support 6 ... Wiring 7 ... Lighting equipment

Continued on the front page (72) Inventor Naoya Matsumoto 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Lighting & Technology Corporation (72) Inventor Shinji Atago 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Lighting & Technology Corporation In-house (72) Inventor Hisanori Sano 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Lighting & Technology Corporation

Claims (4)

[Claims] 1. An arc tube comprising an inert gas for starting, a metal for emission, and a pair of discharge electrodes sealed therein; a lead wire connected to the discharge electrode and sealing out a wall of the arc tube; and the lead. A metal vapor discharge lamp having an external connection portion connected to a wire, and an envelope surrounding the arc tube, wherein an inert gas and an oxygen gas are sealed in the envelope. Features metal vapor discharge lamp. 2. The metal vapor discharge lamp according to claim 1, wherein the inert gas in the envelope is nitrogen gas. 3. The partial pressure of oxygen gas in the envelope is 0.1 torr or more.
4. The method according to claim 1, wherein the pressure is 4 torr.
A metal vapor discharge lamp as described. 4. A metal vapor discharge lamp according to any one of claims 1 to 3, and a lighting fixture body equipped with the metal vapor discharge lamp and provided with a lighting circuit for lighting the metal vapor discharge lamp. A lighting device, comprising: