JPH11144682A - High-pressure discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp capable of preventings reaction of ceramic with a light emitting metal that are light emitting tube materials while the lamp is lit, and providing stable lamp characteristics during the service life with high efficiency. SOLUTION: A light emitting tube 1 consisting of a light-transmissive ceramic is provided in an outer tube. The light emitting tube 1 consists of a main tube part 10, disc-shaped disc parts 11a and 11b secured so as to close openings at both ends of this main tube 10 and having through holes formed at a center, this tube parts 12a and 12b at one end inserted into and secured to the through holes of these discs 11a and 11b. Electrode introducing bodies 14 and 15 at one end at which electrodes 13a and 13b are provided is inserted into the thin tube parts 12a and 12b and sealed therewith so that the electrodes 13a and 13b are positioned in the light emitting tube 1. A surface on a side facing discharge spaces of the discs 11a and 11b form grooves 16a and 16b in which the light emitting metal that is a sealant is retained while the lamp is lit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure discharge lamp using an arc tube made of a translucent ceramic.

[0002]

2. Description of the Related Art A high-pressure discharge lamp using an arc tube made of ceramic is enclosed in an arc tube material and an arc tube in comparison with a high-pressure discharge lamp using an arc tube made of quartz which has been generally used so far. It is expected that stable life characteristics can be obtained because of little reaction with the luminescent metal. For the above-mentioned reason, by increasing the load on the arc tube and increasing the temperature of the arc tube during lighting, the efficiency (lm / W) of the lamp can be increased.

Conventionally, a high-pressure discharge lamp of this type has a pair of electrodes inside and a luminescent metal sealed inside, and has a central section of a discharge vessel as a discharge space, and openings at both ends of the central section. There is known a ceramic arc tube comprising a disk fixed to a portion and a thin tube respectively fixed to the disk (Japanese Patent Application Laid-Open No. 6-196131).

[0004]

In such a conventional high-pressure discharge lamp, when the lamp is lit vertically, liquid-state luminescent metal accumulates on the surface of the lower disk located on the side of the discharge space, and the electrode becomes an electrode. It has been found that in the vicinity where the temperature is high, the ceramic as the arc tube material reacts with the luminous metal, causing an increase in the lamp voltage and a decrease in the luminous flux maintenance ratio, and the lamp characteristics are remarkably deteriorated.

[0005] In addition, a sufficient initial characteristic can be obtained even when the conventional high pressure discharge lamp has a shape in which a tapered portion is provided instead of a flat disk as the shape of the arc tube. However, even with the tapered portion, the above-described reaction between the ceramic, which is the arc tube material, and the luminous metal occurs in the same manner, and in this case, the enclosure exists near the base of the electrode, and therefore, the electrode and the luminous metal exist. Since the distance to the part is shorter than that using a disk, the temperature of the part where the luminescent metal is stored is high, and the reaction between the luminescent tube material ceramic and the luminescent metal is further promoted. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and prevents a reaction between a ceramic, which is a luminous tube material, and a luminous metal during lamp operation, thereby providing a highly efficient, stable lamp for a lifetime. It is an object of the present invention to provide a high-pressure discharge lamp having characteristics.

[0007]

SUMMARY OF THE INVENTION A high pressure discharge lamp according to the present invention comprises a tubular main tube portion, disk portions provided at both ends of the main tube portion, and thin tube portions provided respectively on the disk portion. A ceramic luminous tube having a pair of electrodes inside, and a luminous metal sealed inside, wherein a groove is formed on the surface of the disk portion located inside the luminous tube. Have.

For this reason, the luminous metal accumulates in the groove formed on the surface of the disk portion located inside the luminous tube, so that the contact area between the luminous tube and the luminous metal can be reduced when the lamp is turned on, and the luminous metal can be reduced. Since the light is stored in the groove, the light-emitting metal is hidden behind the electrode, so that the temperature of the portion where the light-emitting tube and the light-emitting metal are in contact can be lowered, preventing the reaction between the light-emitting tube and the light-emitting metal, and shortening the life. Medium stable lamp characteristics can be obtained.

The high-pressure discharge lamp of the present invention comprises a tubular main tube, tapered portions provided at both ends of the main tube, and ends inserted into the tapered portion. A thin tube portion, comprising a pair of electrodes inside, a ceramic light emitting tube in which a light emitting metal is sealed, and an end of the thin tube portion inserted into the tapered portion is inside the light emitting tube. And a groove is formed at a boundary between the tapered portion and an end of the thin tube portion protruding into the arc tube.

For this reason, the luminescent metal is accumulated in the groove formed at the boundary between the tapered portion and the thin tube portion, and the contact area between the luminescent tube and the luminescent metal during lamp operation can be reduced.
In addition, since the luminescent metal accumulates in the groove, the luminescent metal is hidden behind the electrode, so that the temperature of the portion where the luminous tube and the luminous metal are in contact can be lowered, and the reaction between the luminous tube and the luminous metal can be reduced. And stable lamp characteristics can be obtained throughout the life.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a high-pressure discharge lamp having a lamp power of 150 W (hereinafter, referred to as a first embodiment) of the present invention.
In the product A of the present invention), an arc tube 1 made of a translucent ceramic, which will be described later, is provided in an outer tube 9 one end of which is sealed by a stem 5. Arc tube 1 made of translucent ceramic
A light-transmitting tube 2 made of quartz is provided so as to surround the light emitting tube 1, and metal plates 3 a and 3 b are provided so as to close openings at both ends of the light-transmitting tube 2. ing.

The external lead wires 4a derived from the arc tube 1
4b penetrates the metal plates 3a, 3b and is connected to stem lines 6a, 6b derived from the stem 5, respectively.

The external lead wire 4a is connected to the stem wire 6b via the power supply wire 7. In addition, stem 5
The base 8 is provided on the outer tube 9 on the side where is provided.
Further, nitrogen is sealed in the outer tube 9.

As shown in FIG. 2, an arc tube 1 made of a translucent ceramic has a main tube portion 10 having an outer diameter of 10 mm and a central portion fixed to close both end openings of the main tube portion 10. Disk-shaped disk portions 11a and 11b having through holes;
One end is inserted into and fixed to the through-hole of each of the disk portions 11a and 11b.
b.

Electrode introduction bodies 14 and 15 having electrodes 13a and 13b provided at one end thereof in the thin tube sections 12a and 12b.
Are inserted and sealed so that the electrodes 13a and 13b are located in the arc tube 1.

The electrode introduction members 14 and 15 are connected to the electrodes 13a and 1
3b, electrode rods 14a and 15a for holding the electrodes 13a and 13b at one end, halide-resistant parts 14b and 15b made of Mo (molybdenum), and external lead wires 4a and 4b.
Consists of The external lead wires 4a, 4b are made of Nb (niobium) having a thermal expansion coefficient close to that of the thin tube portions 12a, 12b.

The surfaces of the disk portions 11a and 11b located inside the arc tube, that is, the surfaces facing the discharge space,
During the operation of the lamp, grooves 16a and 16b are formed for storing the light-emitting metal as an enclosure. The width of the grooves 16a and 16b is 0.5 mm, and the depth is 1 mm. The arc tube 1 contains a predetermined amount of mercury and Ar as a starting rare gas.
Is enclosed, dysprosium as metal halide,
It contains iodides such as thallium and sodium.

Next, using the product A of the present invention and a high-pressure discharge lamp (hereinafter referred to as comparative product A) having the same structure as that of the product A of the present invention using a disk portion provided with no groove, Retention rates were compared. The result is shown in FIG. In addition,
The luminous flux maintenance factor of the product A of the present invention is shown by a solid line, and the luminous flux maintenance factor of the comparative product A is shown by a broken line.

In the comparative product A, the reaction between the ceramic, which is the arc tube material, and the luminous metal was violent, and the luminous flux maintenance factor was 70% after 3000 hours of lighting, 65% after 4000 hours of lighting, and 6000 hours after lighting. 61 in time
%. On the other hand, the product A of the present invention has 3
At 000 hours, the luminous flux maintenance rate was 82%,
The luminous flux maintenance ratio was as good as 79% at 00 hours and 75% even at 6000 hours after lighting.

In the above embodiment, the lamp power 15
Although the description has been given of the case of 0 W, the lamp power is 35 W, 7 W
The same effect can be obtained even when used at 0 W and 100 W.

Next, a high-pressure discharge lamp according to a second embodiment of the present invention (hereinafter, referred to as a product B of the present invention) will be described.

As shown in FIG. 4, in the high-pressure discharge lamp according to the present embodiment, the disk-shaped disk portions 11a and 11b in the above-described embodiment are connected to the main pipe portion 17 as tapered portions 19a and 19b. , And the tapered portions 19a, 1
The ends of the thin tube portions 12a and 12b are inserted into the openings of the tapered portion of the tapered portion 9b, and the end portions of the thin tube portions 12a and 12b are provided so as to protrude by 1 mm into the arc tube 20, so that the tapered portions 19a and The V-shaped grooves 18a and 18b are formed at the boundary between the slope located inside the arc tube 19b and the ends of the narrow tube portions 12a and 12b protruding inside the arc tube. This is the same as the high-pressure discharge lamp of the embodiment. With such a configuration, the product B of the present invention is
During the operation of the lamp, the light-emitting metal, which is an enclosure, accumulates in the grooves 18a, 18b.

Next, the product B of the present invention and a high-pressure discharge lamp (hereinafter referred to as a comparative product B) having the same structure as the product B of the present invention but having no groove 18 were used. A comparison was made. The result is shown in FIG. The luminous flux maintenance factor of the product B of the present invention is shown by a solid line, and the luminous flux maintenance factor of the comparative product B is shown by a broken line.

The comparative product B had a luminous flux maintenance ratio of 70% in 2000 hours, and the inner wall of the arc tube near the electrode was eroded by reacting with the sealed material. On the other hand, the product B of the present invention provided with the groove 18 exhibited a very good luminous flux maintenance factor, and it was confirmed that the luminous flux maintenance factor was maintained at 80% even after 6000 hours of lighting.

[0026]

As described above, according to the high-pressure discharge lamp of the present invention, the contact area between the arc tube and the enclosure can be reduced by providing a groove for storing the liquid enclosure in the arc tube main tube. By suppressing the reaction between the filling and the arc tube, stable lamp characteristics can be obtained during lighting.

[Brief description of the drawings]

FIG. 1 is a front view of a high-pressure discharge lamp according to a first embodiment of the present invention.

FIG. 2 is a sectional front view of the arc tube.

FIG. 3 is a diagram showing the relationship between the luminous flux maintenance ratio of the product A of the present invention and the comparative product A.

FIG. 4 is a sectional front view of an arc tube of a high-pressure discharge lamp according to a second embodiment of the present invention.

FIG. 5 is a diagram showing the relationship between the luminous flux maintenance ratio of the product B of the present invention and the comparative product B.

[Explanation of symbols]

 1,20 arc tube 2 translucent cylinder 3a, 3b metal plate 9 outer tube 10,17 main tube portion 11a, 11b disk portion 12a, 12b thin tube portion 13a, 13b electrode 16a, 16b, 18a, 18b groove 19a, 19b taper Department

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichi Sugimoto 1-1, Yukicho, Takatsuki-shi, Osaka Matsushita Electronics Co., Ltd. (72) Inventor Fumiki Nakayama 1-1-1, Yukicho, Takatsuki-shi, Osaka Matsushita Electronics (72) Inventor Takashi Yamamoto 1-1, Yukicho, Takatsuki-shi, Osaka Matsushita Electronics Co., Ltd.

Claims (2)

[Claims] 1. A main tube having a cylindrical shape, disk portions provided at both ends of the main tube portion, and thin tube portions provided on each of the disk portions, and having a pair of electrodes inside. ,
A high-pressure discharge lamp further comprising a ceramic arc tube in which a light-emitting metal is enclosed, and a groove formed in a surface of the disc portion located inside the arc tube. 2. A cylindrical main pipe part, a tapered part provided at both ends of the main pipe part, and a narrow pipe part provided with an end inserted into the tapered part. A ceramic light emitting tube having a pair of electrodes and a light emitting metal encapsulated therein is provided, and an end of the thin tube portion inserted into the tapered portion is provided so as to protrude inside the light emitting tube, and the taper is provided. A high-pressure discharge lamp characterized in that a groove is formed at a boundary between the portion and an end of the thin tube portion protruding into the arc tube.