JPS63175328A - Metal vapor discharge lamp - Google Patents

Abstract

PURPOSE:To obtain safety and handling facility when a radioactive substance is sealed in a luminous tube by sticking and holding the radioactive substance on a hole part bored in a holder. CONSTITUTION:Buffer metal, metal halide, and a starting inert gas are sealed in a luminous tube 4, and besides a radioactive substance holder member 18 is sealed in the tube. A radioactive substance 21 is sticked and held on a hole part 19 which is bored in a cylindrical holder 20 of the holder member 18. When a voltage is applied to this lamp, a current flows via a bimetal 17, a glow discharge lamp 16, and a currentlimitting resistor 15. A pulse voltage is generated by continuity and discontinuity of the current flowing due to opening and closing operations of a bimetal contact in the lighting tube 1 6, so that auxiliary discharge between a main electrode 7 and a starting auxiliary electrode 9 advances to main electrodes 7 and 8 so as to generate main arc discharge.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a metal vapor discharge lamp in which a radioactive substance is sealed within one arc tube to facilitate starting.

(Prior Art) In general, metal vapor discharge lamps such as metal halide lamps and high-pressure sodium lamps have high luminous efficiency, so it is necessary to apply a sufficiently high voltage to start them. However, in recent years, lamps have been developed that are compatible with high-pressure mercury lamps by starting them using mercury lamp ballasts, and this type of lamp requires a device to lower the starting voltage so that it can be started at a lower voltage. be done.

As a means of lowering the starting voltage.

The present applicant has proposed, for example, Japanese Patent Publication No. 34220/1983 to enclose a radioactive substance in an arc tube. The half-life of these proposals is 0.5 to 10 years.
By enclosing a radioactive substance in the arc tube, the trigger for the discharge at startup depends on the electrons supplied from the radioactive substance, which serves as the seed for the initial discharge.

However, the above-mentioned radioactive substances tend to have an adverse effect on the human body, and sufficient care is required in handling them. So 9
As described in Japanese Patent Application Laid-Open No. 57-9047, the present applicant has proposed a safety measure in which radioactive substances are dispersed and sealed in a ceramic body and sealed inside the arc tube, and then further precautions are taken. As a precautionary measure, they also proposed a method of sealing the surface of the ceramic body in which the radioactive substance was dispersed and sealed with a non-radioactive, heat-resistant, and corrosion-resistant coating such as glass (Japanese Patent Publication No. 34224/1983).

(Problems to be Solved by the Invention) However, the above-mentioned means for sealing with glass naturally increases the step of covering with glass, and the thickness of the glass layer becomes uneven, which is sometimes not desirable for stability reasons. Therefore, if the thickness of the glass layer is made thicker, the transmittance of radiation from radioactive substances decreases, which reduces the effect of improving the starting characteristics, which is the original purpose. .

Therefore, the present invention is intended to solve the above problems.

An object of the present invention is to provide a metal vapor discharge lamp which is safe and easy to handle in spite of a simple means for sealing a radioactive substance in an arc tube.

[Structure of the invention]

(Means for Solving the Problems) In the metal vapor discharge lamp of the present invention, when carrying a radioactive substance on a carrier made of ceramic, for example, and enclosing it in the arc tube, the radioactive substance is placed in a hole provided in the carrier. It is constructed in such a way that it can be applied and carried on the body.

(Function) With such a configuration, the radioactive substance is hidden within the pores of the carrier, and therefore does not come off in the smear test. That is, when the radioactive material carrier is checked with a counter or the like to see if radiation is emitted from the surface of the paper, no radiation is detected, and as a result, the radioactive material does not move from the carrier to the paper.

Therefore, it is safe and easy to handle, and the two-discharge lamp can be started easily. Furthermore, since it is sufficient to simply provide a hole in the carrier and deposit the radioactive material into the hole, its manufacture is extremely simple.

(Embodiment) An embodiment of the present invention will be described below based on drawings in which it is applied to a metal halide lamp.

Figure 1 shows a longitudinal cross-sectional view of the lamp. In Figure 1, (1) is an outer tube, one end of which is sealed with a stem (2), and a cap (3). It is covered. (4) is an arc tube made of quartz glass, etc.
(5) and (6) are held in the center of the outer tube (1). Inside the arc tube (4) there are main electrodes (7), (
8) are arranged oppositely, and an auxiliary starting electrode (9) is placed close to one main electrode (power).
7) is electrically connected to the support (5), and this support (5) is electrically connected to the cap (3) via the lead-in wire (II) sealed through the stem (2). There is.

The other main electrode (8) is connected to another lead wire Q3 via lead wire 1υ, and this lead wire α is connected to the stem (2).
The starting auxiliary electrode (9) is connected to the eyelet terminal (13) of the cap (3) through the starting auxiliary resistor I and the current limiting resistor σ9.
At the same time, the auxiliary starting resistor B4 is connected to the lead-in line a through the glow tube (Le and a normally closed bimetal switch αη as a thermally responsive element). The reactor is filled with mercury as a buffer metal, metal halides such as scandium iodide (ScI), NaI, and a rare starting gas such as argon gas.

Furthermore, a radioactive substance carrier (IQ) is enclosed.This radioactive substance carrier (18 is a hole penetrating the center (18) as shown in FIG. 2 (perspective view) and FIG.
A radioactive substance (21) such as 147Pm is deposited and supported in the hole C19 of the cylindrical carrier (2), which is made of, for example, ceramic and is provided with a radioactive material (21).

Note that the radioactive material carrier (I8) is injected into the arc tube (4) through its exhaust pipe before it is sealed, so that the radioactive material carrier (I8) is formed in a size that allows it to pass through the exhaust pipe. .

The ceramic used as the support (1) is, for example, a nonmetallic oxide such as silicon oxide (Sin2).

Aluminum oxide (AJz03)-sodium oxide (N
azO) - magnesium oxide (MgO), beryllium oxide (BeO).

Metal oxides such as titanium oxide (TiO) and calcium oxide (CaO), aluminum carbide (A14Cs), sodium carbide (NazCz) *Calcium carbide (C
metal carbides such as aCz), aluminum nitride (AgN
), thorium nitride (Na3N)-magnesium nitride (
It is formed of a metal nitride such as Mg3Nz), an oxide of a high melting point metal such as tungsten or molybdenum, or an oxide of the same metal as the encapsulated luminescent metal.

Further, the carrier (1) is not limited to ceramic, but may be formed of, for example, an amorphous glass-like material, a high melting point metal such as tungsten or molybdenum, or a metal such as the same metal as the encapsulated luminescent metal.

In short, any material may be used as long as it can handle the high temperature of the arc tube during lighting and does not adversely affect the characteristics of the discharge lamp.

In addition, radioactive substances (2
As for 1), it is desirable that the half-life is relatively short, and the half-life is preferably 0.5 years or more and 104 years or less. For example, carbon-14 ("C), sodium-22 (22Na)
, calcium 45 (“Ca), iron 55 (S5Fe).

Cobalt 60 ("Co), 27 pieces/L/s3 ("N
i) + Zinc 65 (65Zn), Manganese 54 (”
Mn) *Stomitutium 90 (903r),
Ruthenium 106 ("'Ru), Silver 110 ("" A
g) + Antimony 125 (12BSb), Cesium 134 (13'Cs).

Cesium A 137 (13'Cs), Barium 133 (
133B a) + Cerium 144 (144Ce
) + promethium A 147 ("Pm), europium 1 s 4 ("Eu) + europium 1
55 (155Eu) #Gold 195 (''Au), Thallium 204 (''Tg), Actinium 227 (''Ac
), Americium 241 (24' Am) + Curium 242 (24"Cm), Curium 244
(”' Cm) *Californium zsz (”Cf)
, lead 210 (''Pb), radium 226 (22'
At least one of the following is selectively employed: Ra)*radium-228 (228Th), and the like.

Furthermore, the above-mentioned radioactive substance (19) is sealed with a radiation capacity of 100 microcuries or less per lamp.

The metal halide lamp has such a configuration.

When voltage is applied via a ballast (not shown).

Since the bimetal switch (171) is closed, current flows through the bimetal C171, Glo-1 lighting tube (1G, current limiting resistor US, and Glo-1 lighting tube (11) is activated. To open and close the bimetal contact of the Glo-1 lighting tube αe. Due to the accompanying interruption of current conduction, a pulse voltage is generated by the choke inductance of the ballast (not shown in the figure).And,
Auxiliary discharge is started between one main electrode (7) and the starting auxiliary electrode (9). This auxiliary discharge is connected to the main electrode (force, (8)
The main arc discharge develops between the arc and the main arc discharge. After starting, the metal halide sealed in the arc tube (4) evaporates and emits light. Additionally, the arc tube voltage increases as the metal halide evaporates.

As the temperature of the arc tube (4) rises, the bimetal switch (171) is opened in response to this heat. Therefore, when the lamp reaches stable lighting, no current flows to the lighting tube (1119) and the 1 lighting tube ae Since the bimetal contact closes, the auxiliary starting electrode (9) and the adjacent main electrode (7) are kept at the same potential: no potential is applied between them through the quartz arc tube; No defects such as recrystallization or cracks occur.

However, the above lamp has a radioactive material (2) inside the arc tube (4).
1), the radioactive substance (21) emits initial electrons that act as a trigger for discharge, that is, seeds, so that starting is performed quickly and the starting voltage is low. In other words, the initial electrons emitted from the radioactive substance (21) ionize the rare gas in the vicinity, and when a pulse voltage is applied while a small amount of this ionized gas is present, the insulation inside the arc tube (4) Destruction will occur and start.

If the radioactive substance (21) is not enclosed in the arc tube (4), no ionized gas is generated and startup is difficult. In other words, the discharge does not start until ionized gas is generated by cosmic rays and natural radiation from the earth, etc. These cosmic rays and natural radiation from the earth are extremely small, occurring at a rate of about once every 20 seconds or more. This increases the startup wait time. In other words, the starting voltage of a conventional lamp in which the radioactive substance is not sealed in the arc tube is approximately 4.5 mm per lighting period of 1,000 hours.
000V.

While the voltage was about 5.0 OOV for 2,000 hours, the lamp of the present invention had a voltage of about 800 V for 1,000 hours and about 5 oOV for 2,000 hours, and the effect was extremely remarkable.

Moreover, since the radioactive substance (21) is deposited on the hole (19) provided in the cutout of the carrier I2, manufacturing is not only extremely easy, but also the radioactive substance (21) is carried in the hole α] Since the radioactive substance (21) is hidden inside the carrier, there is no risk of it peeling off in the smear test, and there is no risk of it adhering to the human body, so it can be handled safely. But, ``S1: It's fine, and you can heat it further to prevent it from burning.

4 to 6 show the forms of radioactive substance carriers (18) of different embodiments, and the same parts as in the previous embodiments are denoted by the same reference numerals, and their explanations will be omitted.

In the case shown in FIG. 4, the hole α9 provided in the carrier (2) does not penetrate through the carrier (20).

In the case shown in Fig. 5, a plurality of holes C1'J, (19.
Established...

Radioactive material (21
) coated with

In the case shown in Figure 6, radioactive material (21
) is applied, the inner surface of both openings is shaved to create a tapered part (19
a), (19a) are formed.

Since the radioactive substance (21) is not coated around both openings of the hole H, the possibility of it coming off when it comes into contact with other objects is further reduced.

Note that the present invention is not limited to metal halide lamps.

It can also be applied to other metal vapor discharge lamps, such as high pressure sodium lamps and high pressure mercury lamps.

〔Effect of the invention〕

As described above, according to the configuration of the present invention, the radioactive substance is hidden in the hole provided in the carrier, so it does not peel off in the smear test, and it can be handled safely and is extremely easy to manufacture. This makes it possible to provide a metal vapor discharge lamp with excellent starting characteristics.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, FIG. 1 is a longitudinal sectional view of a metal halide lamp, FIG. 2 is a perspective view of a radioactive material carrier, and FIG. 3 is the same (longitudinal sectional view, Figures 4 to 6
Each figure shows a longitudinal cross-sectional view of a different radioactive substance carrier. (1)... Outer tube, (4)... Arc tube. (Force, (8)...Main electrode, 1 second...
Radioactive substance carrier. (11... Hole, wire... Support. (21)... Radioactive material.

Claims (1)

[Scope of Claims] 1) A metal vapor discharge lamp in which a starting rare gas, mercury, and a luminescent metal are sealed in an arc tube, and a radioactive material carrier is further enclosed, in which the radioactive material is provided on the carrier. A metal vapor discharge lamp characterized in that the lamp is adhered to and supported in a hole. 2) The metal vapor discharge lamp according to claim 1, wherein the carrier is made of ceramic.