JPH0773853A - Single-side sealed metal vapor discharge lamp - Google Patents

Abstract

PURPOSE:To prevent the exfoliation or damage of that part in a sealed tube which has undergone a sealing process. CONSTITUTION:A metal vapor discharge lamp is equipped with a bulb 1 in which mercury, starting gas, halogen metal, etc., are encapsulated, an electrode 4 protruding to the inside of the bulb 1, an outer lead 5 for supplying high voltage pulses, and a sealed tube 6 in which a molybdenum foil 6 for connection of the lead with the electrode is embedded. The connections of the electrode 4, molybdenum foil 6 and 16 are made with steps to one another so that the connecting positions have the maximum separating distances relative to the finite length across the width of the sealed tube 2. As a result, the neighboring part is free from the influence of the stress and strain generated in the connection part of the electrode with the molybdenum foil, so that the inside of the sealed tube will never undergo exfoliation or breakage, and the characteristics of discharge lamp are enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-sealed metal vapor discharge lamp, and more particularly, a pair of electrodes are embedded in a sealed tube attached to one end of a bulb, and mercury, starting gas and halogen metal are contained in the bulb. The present invention relates to an improvement of a single-sealed metal vapor discharge lamp in which is sealed.

[0002]

2. Description of the Related Art Generally, as a good quality lighting in a building or the like, it has excellent features such as high lamp efficiency, a large luminous flux per lamp, a long life, and a small light source, but high brightness. High intensity discharge (High Intensity D)
ischarge -HID-) lamp is used.

This high-intensity discharge lamp is used as a general term for mercury lamps, metal vapor (metal halide) lamps, high-pressure sodium lamps, etc., and is excellent in illumination quality and economical efficiency. Of these, metal vapor discharge lamps are widely used as lighting for shops and hotel lobbies.

FIG. 5 shows the structure of a conventional single-side sealed metal vapor discharge lamp. In FIG. 5, a single-sealed metal vapor discharge lamp has a slightly flat spherical bulb 1, a sealing tube 2 joined in a sealed state to one of the slightly flat curved surfaces of the bulb 1, and this sealing tube 2 is joined. The exhaust pipe 3 that is joined to the curved surface that faces the curved surface that is formed is basically provided. The sealing tube 2 includes a pair of electrodes 4 and 4 formed of, for example, tungsten, a pair of outer leads 5 and 5 connected to the electrodes 4 and 4, and an electrode 4 and an outer lead 5, respectively. Molybdenum (Mo) connected in pairs
A pair of foils 6 and 6 are embedded, and the tips of the electrodes 4 and 4 project into the bulb 1. Molybdenum foil 6
Is a fusion pressure portion used as a sealing conductor, and is an electrode 4 sealed to a sealing tube 2 made of quartz glass or the like.
Also, the connection portion of the outer lead 5 is prevented from being disconnected by the pulse voltage supplied via the lead 5. The pair of electrodes 4, the outer lead 5 and the molybdenum foil 6 are connected and integrated by ordinary spot welding, inserted into the sealing tube 2, and then hermetically sealed by pinch sealing using an ordinary oxyhydrogen burner. Crimped and buried.

A predetermined amount of mercury, a starting gas such as argon (Ar), xenon (Xe) and krypton (Kr), and a small amount of this starting gas are mixed in the valve 1 through the exhaust pipe 3. Dysprosium (Dy), Scandium (Sc),
Thulium (Tm), Holmium (Ho), Sodium (Na)
・ Thallium (Tl), neodymium (Nd), cesium (Cs), and other iodide or bromide trace amounts of halogen metals are enclosed. In addition, the exhaust pipe 3 is provided with the above-mentioned encapsulating material in the valve 1
After being sealed inside, the tip is hermetically cut (chip) in the vicinity of the neck portion connected to the valve 1 using an oxyhydrogen burner.

Since the respective members of the electrode 4 and the outer lead 5 embedded in the sealing tube 2 have different coefficients of thermal expansion from the quartz glass forming the sealing tube 2, stress strain occurs after sealing. In order to reduce this stress strain as much as possible, molybdenum foil having a coefficient of thermal expansion close to that of quartz glass is used as a connecting member.

The metal vapor discharge lamp thus constructed is generally used as a lighting device in which a lighting fixture 32 is formed by being housed in a reflector 31 having a socket 30 as shown in FIG.

[0008]

However, even if a molybdenum foil having a thermal expansion coefficient close to that of quartz glass is used,
The maximum stress strain occurs at each connection, especially at the connection between the electrode 4 and the molybdenum foil.

Therefore, since the single-side sealed metal vapor discharge lamp having this kind of structure is formed such that the left and right buried lengths of the pair of electrodes are the same, the connecting portion between the electrodes and the molybdenum foil is sealed. The left and right sides of the tube 2 are located at the same length. Therefore, the separation distance between the left and right connecting parts becomes short, and stress strain occurs after the sealing process or when the lamp blinks, and this stress strain causes peeling or damage, which causes serious leakage such as airtight leak or lamp rupture. There was a problem that an accident occurred.

This problem can be solved by enlarging the width of the sealing tube 2 and widening the left-right separation distance. However, with this structure, the joint area between the valve 1 and the sealing tube 2 increases. Since the amount of heat that escapes from the bulb 1 to the sealing tube 2 when the lamp is turned on is large, a sufficient lamp cooling temperature cannot be obtained, and various characteristics such as good brightness, color rendering and color temperature can be obtained. There is a problem of disappearing.

The present invention has been made in view of the above problems, and it is possible to prevent peeling or damage of the sealed portion after sealing processing or when the lamp blinks, and airtight leakage or valve rupture due to these. At the same time, it is an object of the present invention to provide a single-sealed metal vapor discharge lamp having various characteristics such as brightness, color rendering, color temperature, etc. of the lamp.

[0012]

In order to solve the above-mentioned problems, a single-sealed metal vapor discharge lamp according to the present invention is internally sealed with mercury, a starting gas, and a halogenated substance, and has a pair of left and right discharges. A substantially spherical bulb having electrodes protruding inward, the pair of electrodes, a pair of outer leads for supplying a pulse voltage for discharge to the electrodes, a pair of electrodes, and a pair of molybdenum connecting the outer leads. In a single-sealed metal vapor discharge lamp comprising a sealing tube that is fused and bonded to the bulb outer wall so that the electrodes project into the bulb while integrating and embedding the foil in each bulb, the molybdenum foil and The left and right connecting parts are displaced so that the positions of the left and right connecting parts with the electrode are separated by the maximum distance with respect to the same width in the sealing tube. That.

[0013]

Since the present invention has the above-mentioned structure, the connecting portions between the electrode and the molybdenum foil, to which the largest stress strain is applied, should be separated as much as possible in the limited width direction of the sealing tube in the left and right portions. You can For this reason, the strain between the left and right connecting portions can be reduced, and not only peeling and damage of the sealing portion can be significantly suppressed, but also airtight leakage and rupture due to these can be prevented.

Also, regarding the characteristics of the lamp such as brightness, color rendering, color temperature, etc., it is necessary to form a wide separation distance between both connecting portions without increasing the joint area between the bulb and the sealing tube as described above. Therefore, the maximum cooling temperature of the lamp can be set sufficiently high, and good various characteristics can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a single-sealed metal vapor discharge lamp according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a sealed single metal vapor discharge lamp according to the first embodiment of the present invention. In FIG. 1, the same components as those of the conventional single-sealed metal vapor discharge lamp described with reference to FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted. The single-sided sealed metal vapor discharge lamp of the first embodiment includes a bulb 1, a sealing tube 2, and an exhaust tube 3 each having a pair of electrodes projecting into the bulb 1 inside the sealing tube 2. 4, a pair of outer leads 5 for supplying a pulse voltage to the electrodes 4, a molybdenum foil 6 having a normal length for connecting the electrodes 4 and the outer leads 5 on one side, and the electrodes 4 and the outer leads on the other side. It is composed of a molybdenum foil 16 which is shorter than usual and which connects between the five.

The sealing tube 2 has an inner diameter of about 10 mm and a length of about 20 mm. One of the electrodes 4 is made of tungsten containing thorium and has a shaft diameter of 0.8 mm and a length of 8.5 to 11 mm (any value in 0.5 mm increments).
Is formed. The other side of the electrode 4 is also made of tungsten containing thorium with a shaft diameter of 0.8 mm and a length of 8 mm.
Is formed. The molybdenum foils 6 and 16 are wide
It is 2.0 mm thick and 20 microns thick, and the length of foil 6 is 1.
The foil 16 is formed to a size of about 10 mm with a thickness of 1.5 mm. The outer lead 5 has a wire diameter of 10 mm and a length of 20 mm.
Electrode 4, outer lead 5 and molybdenum foil 6 and 1
6 is joined and integrated by spot welding.

The above-mentioned integrated pair of power feeding portions are inserted into the inside of the sealing tube 2, and then the sealing tube 2 is heated by using a normal oxyhydrogen burner and the members inside the tube 2 are hermetically sealed by pinch sealing. Buried in. Then, the valve 1 was attached to a general exhaust system, and 30 mg of mercury in the valve 1 was mixed with xenon (Xe) as a starting gas in a composition ratio of 1 to 5 scandium iodide (ScI) -sodium iodide ( NaI) 4
Encapsulate mg under a pressure of 200 Torr. Finally, the exhaust pipe 3 is airtightly cut (chip) from the neck portion using an oxyhydrogen burner to complete the lamp.

Regarding the difference in length between the molybdenum foils 6 and 16, after various experiments, the difference in length was 1.
Those with a step of 5 mm or more did not show any abnormality in the test after sealing and at the time of blinking. Details of the durability test are as follows.

That is, the difference in length is 0.5 mm, 1.0 mm,
6 of 1.5mm, 2.0mm, 2.5mm and 3.0mm
10 pieces of single-ended metal vapor discharge lamps each having a rated output of 100 W set in stages are manufactured. Assemble and embed the power supply unit. These 60 test pieces in total were completed as lamps according to the above process. Peeling or breakage of the sealing part, and airtight leakage due to these, when the lamp having the sealing part 2 of these 6 stages is flashed under the condition of being used for 1 hour after sealing and being turned off for 10 minutes after use. The presence or absence of rupture of the valve or the like was visually observed. Further, various characteristics such as the brightness, color rendering and color temperature of the lamp at the rated output were measured.

As a result, with respect to those having a difference of 0.5 mm, peeling of the sealing portion and airtight leakage due to the peeling occurred in one after sealing and before use and after flashing test, two in total. . Further, in the case where the difference of 1.0 mm was provided, one piece was peeled off at the sealing portion after the blinking test. On the other hand, regarding the prototypes with a difference of 1.5 mm or more, no abnormality was observed after sealing or after the flashing test. Therefore, it is understood that the effect of the present invention can be sufficiently demonstrated if the difference in length between the molybdenum foils 6 and 16 is at least 1.5 mm or more.

It should be noted that the results of the above experiments were almost the same even when the shape and material of the electrodes were changed or when the method of joining the electrodes and the molybdenum foil was changed. However, the same was true when the shape of the valve or the sealing tube was changed or when the method of burying the sealing member was changed to another method.

Further, even when the rated output of the lamp, the blinking condition, the composition of the enclosed halogen metal and the starting gas, the amount of the enclosed gas, etc. were changed, no significant difference was observed in the results.

Next, with reference to FIG. 2, a single-sealed metal vapor discharge lamp according to a second embodiment of the present invention will be described.

The single-sealed metal vapor discharge lamp according to the second embodiment has a peculiar structure for compensating for the malfunction of the discharge lamp according to the first embodiment. In this type of discharge lamp, it is necessary to apply a high-voltage (several kV or more) pulse voltage to the electrode 4 via the outer lead 5 in order to instantly restart. However, in the discharge lamp as shown in FIG. 1, since the gap between the two outer leads 5 and 5 is not sufficiently secured, a high-voltage pulse tends to fly between the two leads 5 and 5 for a moment. There was a problem that the automatic restart was hindered.

Therefore, in order to secure a gap between the outer leads, the outer leads 15 connected to one molybdenum foil 16 are led out from the side of the sealing tube 2 to the outside of the tube.

With this structure, a sufficient gap is secured between the outer leads 5 and 15 so that a smooth lighting operation can be ensured even when the light is re-lighted instantaneously.

FIG. 3 shows a piece-sealed metal vapor discharge tube according to the third embodiment of the present invention. The discharge tube according to the third embodiment is a modification of the second embodiment, and is configured such that both outer leads 15 and 15 both project laterally.

Next, a single-sealed metal vapor discharge lamp according to the fourth embodiment of the present invention will be described with reference to FIG. The discharge lamp of the fourth embodiment is also a modification of the second embodiment like the discharge lamp of the third embodiment. As shown in FIG. 4, this discharge lamp is spot-welded to molybdenum foils 6 and 16, and is provided with a pair of outer leads 25 and 25 that project in a direction away from each other and obliquely downward. With such a configuration as well, similar to the second embodiment, it is possible to prevent the pulse from jumping out when a high-voltage pulse is applied, and to ensure a stable instantaneous relighting.

[0030]

As described above in detail, in the single-sealed metal vapor discharge lamp according to the present invention, mercury, starting gas and halogenated substance are sealed inside, and a pair of left and right electrodes for discharging are inside. And a pair of molybdenum foils connecting the pair of electrodes, a pair of outer leads for supplying a pulse voltage for discharge to the electrodes, a pair of electrodes, and a pair of outer leads. In a single-sealed metal vapor discharge lamp including a sealing tube that is integrally buried in each bulb and is fused to the bulb outer wall so that the electrodes project into the bulb, the electrode and the molybdenum foil are Since the left and right connecting parts are displaced so that they are separated by the maximum distance with respect to the limited width of the sealing tube, peeling or damage of the sealing part after sealing processing or when the lamp blinks It is possible to prevent rupture or the like of the air leakage and valves due to al, the brightness of the lamp color rendition,
It is possible to provide a single-sealed metal vapor discharge lamp having various characteristics such as color temperature.

[Brief description of drawings]

FIG. 1 is a sectional view showing a piece-sealed metal vapor discharge tube according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a piece-sealed metal vapor discharge tube according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a piece-sealed metal vapor discharge tube according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing a piece-sealed metal vapor discharge tube according to a fourth embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a conventional piece-sealed metal vapor discharge tube.

FIG. 6 is a cross-sectional view of a commonly used lighting fixture.

[Explanation of symbols]

 1 Valve 2 Sealing Tube 3 Exhaust Pipe 4 Electrode 5, 15, 25 Outer Lead 6, 16 Molybdenum Foil 30 Socket 31 Reflector 32 Lighting Equipment

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Hikita 4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Lighting & Technology Corporation

Claims (4)

[Claims] 1. A substantially spherical bulb in which mercury, a starting gas, and a halogenated substance are sealed, and a pair of left and right electrodes for discharge project inward, and the pair of electrodes. A pair of outer leads for supplying a pulse voltage, a pair of electrodes, and a pair of molybdenum foils that connect the pair of outer leads are integrally embedded for each, and the electrodes are projected into the bulb. In a single-sealed metal vapor discharge lamp including a sealing tube fused to the bulb outer wall, the positions of the left and right connecting portions of the molybdenum foil and the electrode are at the maximum distance with respect to the same width in the sealing tube. A single-sealed metal vapor discharge lamp characterized in that the left and right connecting parts are displaced so as to be separated from each other. 2. The single-sealed metal vapor discharge lamp according to claim 1, wherein the left and right foils of the pair of molybdenum foils are formed to have different lengths. 3. The single-sealed metal vapor discharge lamp according to claim 1, wherein the outer lead extends in different directions outward from a portion projecting to the outside of the sealing tube. 4. A metal vapor discharge lamp in which the left and right connecting portions of the molybdenum foil and the electrodes are displaced so that the positions of the left and right connecting portions thereof are separated by the maximum distance with respect to the same width in the sealed tube. An illuminating device containing a metal vapor discharge lamp.